feat: doc tags (same as blog tags) (#3646)

* [v2] tags to doc, same as tags to blog - [IN PROGRESS]

- Addition of plugin-content-docs

- Addition of DocTagsListPage in `docusaurus-theme-classic`

! Error exists for this commit towards the theme aspect and help required.

Commit towards #3434

* docs: make tags list page work

* temp: disable onBrokenLinks

* theme bootstrap: create DocTagsListPage

* DocTagsPage added and functionality too

- individual doc tag page added to show docs for that specific tag

* Added all Docs Tags Link

* add some shared tag utils

* move tag tests to _dogfooding

* fix type

* fix some tests

* fix blog test

* refactor blog post tags handling

* better yaml tag examples

* better dogfood md files

* refactor and factorize theme tag components

* finish DocTagDocListPage

* Extract DocItemFooter + add inline tag list

* minor fix

* better typings

* fix versions.test.ts tests

* add tests for doc tags

* fix tests

* test toTagDocListProp

* move shared theme code to tagUtils

* Add new theme translation keys

* move common theme code to tagUtils + add tests

* update-code-translations should handle theme-common

* update french translation

* revert add translation

* fix pluralization problem in theme.docs.tagDocListPageTitle

* add theme component configuration options

* add more tags tests

* add documentation for docs tagging

Co-authored-by: slorber <lorber.sebastien@gmail.com>

packages/docusaurus-plugin-content-docs/src/__tests__/index.test.ts

@@ -60,6 +60,7 @@ const defaultDocMetadata: Partial<DocMetadata> = {
   lastUpdatedAt: undefined,
   lastUpdatedBy: undefined,
   formattedLastUpdatedAt: undefined,
+  tags: [],
 };
 
 const createFakeActions = (contentDir: string) => {
@@ -364,7 +365,23 @@ describe('simple website', () => {
         title: 'baz',
         slug: 'bazSlug.html',
         pagination_label: 'baz pagination_label',
+        tags: [
+          'tag 1',
+          'tag-1', // This one will be de-duplicated as it would lead to the same permalink as the first
+          {label: 'tag 2', permalink: 'tag2-custom-permalink'},
+        ],
       },
+
+      tags: [
+        {
+          label: 'tag 1',
+          permalink: '/docs/tags/tag-1',
+        },
+        {
+          label: 'tag 2',
+          permalink: '/docs/tags/tag2-custom-permalink',
+        },
+      ],
     });
 
     expect(findDocById(currentVersion, 'hello')).toEqual({
@@ -392,7 +409,18 @@ describe('simple website', () => {
         id: 'hello',
         title: 'Hello, World !',
         sidebar_label: 'Hello sidebar_label',
+        tags: ['tag-1', 'tag 3'],
       },
+      tags: [
+        {
+          label: 'tag-1',
+          permalink: '/docs/tags/tag-1',
+        },
+        {
+          label: 'tag 3',
+          permalink: '/docs/tags/tag-3',
+        },
+      ],
     });
 
     expect(getDocById(currentVersion, 'foo/bar')).toEqual({
@@ -579,6 +607,11 @@ describe('versioned website', () => {
       description: 'This is next version of bar.',
       frontMatter: {
         slug: 'barSlug',
+        tags: [
+          'barTag 1',
+          'barTag-2',
+          {label: 'barTag 3', permalink: 'barTag-3-permalink'},
+        ],
       },
       version: 'current',
       sidebar: 'docs',
@@ -586,6 +619,11 @@ describe('versioned website', () => {
         title: 'hello',
         permalink: '/docs/next/',
       },
+      tags: [
+        {label: 'barTag 1', permalink: '/docs/next/tags/bar-tag-1'},
+        {label: 'barTag-2', permalink: '/docs/next/tags/bar-tag-2'},
+        {label: 'barTag 3', permalink: '/docs/next/tags/barTag-3-permalink'},
+      ],
     });
     expect(getDocById(currentVersion, 'hello')).toEqual({
       ...defaultDocMetadata,