feat: npm init docusaurus, yarn create docusaurus (#5635)

* initial create-docusaurus impl

* cleanup

* @docusaurus/init renamed to create-docusaurus

* 0.0.6

* update lockfile

* fix lint

* remove npm2yarn for "npm init" because npm2yarn doesn't convert it and yarn result fails to execute

* prettier

* add correct version

* prettier

* prettier

* prettier

* prettier

* fix annoying --config .prettierrc issue

packages/create-docusaurus/templates/shared/docs/tutorial-extras/_category_.json

@@ -0,0 +1,4 @@
+{
+  "label": "Tutorial - Extras",
+  "position": 3
+}

packages/create-docusaurus/templates/shared/docs/tutorial-extras/manage-docs-versions.md

@@ -0,0 +1,55 @@
+---
+sidebar_position: 1
+---
+
+# Manage Docs Versions
+
+Docusaurus can manage multiple versions of your docs.
+
+## Create a docs version
+
+Release a version 1.0 of your project:
+
+```bash
+npm run docusaurus docs:version 1.0
+```
+
+The `docs` folder is copied into `versioned_docs/version-1.0` and `versions.json` is created.
+
+Your docs now have 2 versions:
+
+- `1.0` at `http://localhost:3000/docs/` for the version 1.0 docs
+- `current` at `http://localhost:3000/docs/next/` for the **upcoming, unreleased docs**
+
+## Add a Version Dropdown
+
+To navigate seamlessly across versions, add a version dropdown.
+
+Modify the `docusaurus.config.js` file:
+
+```js title="docusaurus.config.js"
+module.exports = {
+  themeConfig: {
+    navbar: {
+      items: [
+        // highlight-start
+        {
+          type: 'docsVersionDropdown',
+        },
+        // highlight-end
+      ],
+    },
+  },
+};
+```
+
+The docs version dropdown appears in your navbar:
+
+![Docs Version Dropdown](/img/tutorial/docsVersionDropdown.png)
+
+## Update an existing version
+
+It is possible to edit versioned docs in their respective folder:
+
+- `versioned_docs/version-1.0/hello.md` updates `http://localhost:3000/docs/hello`
+- `docs/hello.md` updates `http://localhost:3000/docs/next/hello`

packages/create-docusaurus/templates/shared/docs/tutorial-extras/translate-your-site.md

@@ -0,0 +1,88 @@
+---
+sidebar_position: 2
+---
+
+# Translate your site
+
+Let's translate `docs/intro.md` to French.
+
+## Configure i18n
+
+Modify `docusaurus.config.js` to add support for the `fr` locale:
+
+```js title="docusaurus.config.js"
+module.exports = {
+  i18n: {
+    defaultLocale: 'en',
+    locales: ['en', 'fr'],
+  },
+};
+```
+
+## Translate a doc
+
+Copy the `docs/intro.md` file to the `i18n/fr` folder:
+
+```bash
+mkdir -p i18n/fr/docusaurus-plugin-content-docs/current/
+
+cp docs/intro.md i18n/fr/docusaurus-plugin-content-docs/current/intro.md
+```
+
+Translate `i18n/fr/docusaurus-plugin-content-docs/current/intro.md` in French.
+
+## Start your localized site
+
+Start your site on the French locale:
+
+```bash
+npm run start -- --locale fr
+```
+
+Your localized site is accessible at `http://localhost:3000/fr/` and the `Getting Started` page is translated.
+
+:::caution
+
+In development, you can only use one locale at a same time.
+
+:::
+
+## Add a Locale Dropdown
+
+To navigate seamlessly across languages, add a locale dropdown.
+
+Modify the `docusaurus.config.js` file:
+
+```js title="docusaurus.config.js"
+module.exports = {
+  themeConfig: {
+    navbar: {
+      items: [
+        // highlight-start
+        {
+          type: 'localeDropdown',
+        },
+        // highlight-end
+      ],
+    },
+  },
+};
+```
+
+The locale dropdown now appears in your navbar:
+
+![Locale Dropdown](/img/tutorial/localeDropdown.png)
+
+## Build your localized site
+
+Build your site for a specific locale:
+
+```bash
+npm run build -- --locale fr
+```
+
+Or build your site to include all the locales at once:
+
+```bash
+npm run build
+```