feat(v2): highlight items in the table of content (#1896)

* feat(v2): highlight items in the table of content

* refactor: move string to const

* refactor(v2): Convert sitemap plugin to TypeScript (#1894)

* Convert sitemap plugin to TypeScript

Test - enabled the sitemap plugin in the v2 website and verified that
the sitemap is created after running `docusaurus build`.

* Addressing review comments

* perf(v2): significantly reduce bundle size & initial html payload (#1898)

* perf(v2): reduce bundle size significantly with super short chunk name and registry

* changelog

* use hash:8 as id for better long term caching

* even shorter filename. slice contenthash

* fix(v2): align search icon on small width device (#1893)

* fix(v2): align search icon on small width device

* nits

* nits

* refactor(v2): refactor dark toggle into a hook (#1899)

* change(v2): refactor dark toggle into a theme

* follow how themes resolve files

* let theme hook to pick up default theme by itself

* perf(v2): reduce memory usage consumption (#1900)

* misc(v1): use primary color for hovered items in table of contents (#1871)

* fix issue#1752

when element in side nav is hovered over the color changes.

* Update main.css

* fix(v1): mobile safari search input misalignment in header (#1895)

* misc(v2): v1 backward compatibility for USE_SSH env var (#1880)

* misc(v2): address comments

* misc(v2): update CHANGELOG

* feat(v2): allow line highlighting (#1860)

* feat(v2): allow line highlighting

* Refactor: use parse-numeric-range for parsing

* Add line highlighting for live code blocks

* feat(v2): add sticky footer (#1855)

* feat(v2): add sticky footer

* Update CHANGELOG-2.x.md

* Update CHANGELOG-2.x.md

* fix(v2): remove empty doc sidebar container (#1870)

* docs: showcase user Amphora (#1873)

* Add Amphora Data link to users

Adds Amphora Data to the list of users

* Add Amphora Data logo

* fix case of image path

* Move Image into users directory

* use black amphora image

* fix(v2): fix search input blur on desktop (#1874)

* docs(v2): showcase user mbt-bundle (#1875)

* feat(v2): postcss should only use stage 3 features instead of stage 2 (#1872)

* feat(v2): add ability expand all items in doc sidebar (#1876)

* feat(v2): add ability expand all items in doc sidebar

* Fix tests

* Refactor: use themeConfig

* Improve docs

* Revert unnecessary  changes

* Refactor: better consistency

* Revert extra change

* Refactor: use useDocusaurusContext to get config value

* chore(v2): update changelog

* chore(v2): update showcase and broken link

* perf(v2): disable hash for css modules localident in dev (#1882)

* perf(v2): disable hash for css modules localident in dev

* changelog

* feat(v2): display footer in docs page for consistency (#1883)

* feat(v2): display footer in docs page

* nits

* address review

* nits

* docs(v2): fix format inline code (#1888)

* docs(v2): add docs on useful client api (#1890)

* docs(v2): add docs on useful client api

* Update docusaurus-core.md

* Update website/docs/docusaurus-core.md

* Update website/docs/docusaurus-core.md

* Update website/docs/docusaurus-core.md

* Update website/docs/docusaurus-core.md

* docs(v2): update config docs (#1885)

* fix(v2): do not show categories with empty items (#1891)

* styles(v2): update infima and fix styles (#1892)

* fix(v2): wrong css class

* v2.0.0-alpha.31

* chore(v2): update docs and changelog

* docs(v2): update plugins, presets and themes docs (#1889)

* docs(v2): update plugins, presets and themes docs

* ideal image plugin

* proof reading

* Merge master

* refactor(v2): Convert sitemap plugin to TypeScript (#1894)

* Convert sitemap plugin to TypeScript

Test - enabled the sitemap plugin in the v2 website and verified that
the sitemap is created after running `docusaurus build`.

* Addressing review comments

* perf(v2): significantly reduce bundle size & initial html payload (#1898)

* perf(v2): reduce bundle size significantly with super short chunk name and registry

* changelog

* use hash:8 as id for better long term caching

* even shorter filename. slice contenthash

* fix(v2): align search icon on small width device (#1893)

* fix(v2): align search icon on small width device

* nits

* nits

* refactor(v2): refactor dark toggle into a hook (#1899)

* change(v2): refactor dark toggle into a theme

* follow how themes resolve files

* let theme hook to pick up default theme by itself

* perf(v2): reduce memory usage consumption (#1900)

* misc(v1): use primary color for hovered items in table of contents (#1871)

* fix issue#1752

when element in side nav is hovered over the color changes.

* Update main.css

* fix(v1): mobile safari search input misalignment in header (#1895)

* misc(v2): v1 backward compatibility for USE_SSH env var (#1880)

* misc(v2): address comments

* misc(v2): update CHANGELOG

* docs(v1): remove user Vasern (#1901)

* misc: update URLs to non-HTML versions (#1902)

* Update README.md - Fix Broken Link

* misc: update URLs to non-HTML versions

* misc(v2): improve index page SEO score

* fix(v2): accessing /docs or /docs/xxxx should not be empty (#1903)

* fix(v2): nested routes should have wildcard/ not found page too

* better fix

* nits

* space

* docs(v2): code block line highlighting (#1904)

* docs(v2): code block line highlighting

* misc: update CHANGELOG

* misc: respond to review

* docs: add line highlighting to the template

* fix(v2): webpack modules resolve should prioritize @docusaurus/core own deps (#1907)

* fix(v2): webpack modules resolve should prioritize own deps

* nits

* feat(v2): simplify blog metadata to minimize number of request (#1908)

* feat(v2): simplify blog metadata to minimize number of request

* remove async

* feat(v2): add ability to set custom HTML in footer items (#1905)

* docs: update configcat user link (#1911)

* fix(v2): docs plugin stability improvement (100% test coverage) (#1912)

* update jest config

* add more tests on docs plugin

* fix(v2): docs plugin should not add routes if there are no docs

* fix

* rm -rf coverage

* nits

* update

* docs(v2): add windows batch instructions for publishing to gh pages (#1914)

* docs: add windows batch instructions for publishing to gh pages

* docs: add windows batch instructions on the v2 website

* fix(v2): custom searchbar should appear even if themeconfig.algolia is undefined (#1909)

* fix(v2): custom searchbar should appear even if themeconfig.algolia is undefined

* nits

* Docs docs

* inaccuracy

* changelog

* nits

* fix(v2): missing/hidden algolia search suggestion result (#1915)

* docs(v2): Redirect component for easy redirect (#1913)

* docs(v2): Redirect component for easy redirect

* typo

* docs

* Update website/docs/docusaurus-core.md

Co-Authored-By: Alexey Pyltsyn <lex61rus@gmail.com>

* Update docusaurus-core.md

* refactor: changes after comments (use custom hooks, code changes, fix bugs)

* fix(v2): regression from prioritizing core node_modules logic (#1917)

* fix(v2): regression from prioritizing core node_modules logic

* nits

* chore: changelog

* docs(v1): showcase user Reactive Interaction Gateway (#1918)

* chore: bump dependencies

* docs(v2): fix typo in advanced plugins (#1926)

* docs(v2): fix typos (#1930)

* docs(v1): fix links in CHANGELOG (#1931)

* fix(v2): @theme/heading should not create anchor if id is not defined (#1925)

* docs(v2): theme, plugin, and preset config (#1929)

* docs(v2): theme, plugin, and preset config

* change tabs to spaces

* change theme example

* misc: use /usr/bin/env bash to increase portability (#1923)

* misc(v1): use Node.js lts version (#1920)

This is much stable and more performant

* chore: downgrade imagemin (#1933)

* fix(v2): add missing key prop in footer items with HTML (#1935)

* fix(v2): fix browser window background (#1936)

* fix(v2): allows to create tabs with only one item (#1934)

* fix(v2): allow to create tabs with only one item

It was not possible to have tabs containing only one tab item, so the code below crashed

```
<Tabs
    defaultValue="SomeFile.js"
    values={[
        { label: "SomeFile.js", value: "SomeFile.js" }
    ]}
>
<TabItem value="SomeFile.js">
    Tab content
</TabItem>
</Tabs>
```

* Update index.js

* fix(v2): remove redundant npm script in classic template (#1937)

* v2.0.0-alpha.32

* chore(v2): changelog

* misc(v2): update TOC highlight

* misc(v2): update CHANGELOG

packages/docusaurus-theme-classic/src/theme/hooks/useTheme.js

@@ -0,0 +1,38 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+import * as React from 'react';
+
+const useTheme = () => {
+  const [theme, setTheme] = React.useState(
+    typeof document !== 'undefined'
+      ? document.querySelector('html').getAttribute('data-theme')
+      : '',
+  );
+  React.useEffect(() => {
+    try {
+      setTheme(localStorage.getItem('theme'));
+    } catch (err) {
+      console.error(err);
+    }
+  }, [setTheme]);
+
+  const setThemeSyncWithLocalStorage = React.useCallback(
+    nextTheme => {
+      try {
+        localStorage.setItem('theme', nextTheme);
+        setTheme(nextTheme);
+      } catch (err) {
+        console.error(err);
+      }
+    },
+    [setTheme],
+  );
+
+  return [theme, setThemeSyncWithLocalStorage];
+};
+
+export default useTheme;