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-utils-validation/src/validationSchemas.ts

@@ -6,6 +6,8 @@
  */
 import Joi from './Joi';
 import {isValidPathname} from '@docusaurus/utils';
+import type {Tag} from '@docusaurus/utils';
+import {JoiFrontMatter} from './JoiFrontMatter';
 
 export const PluginIdSchema = Joi.string()
   .regex(/^[a-zA-Z_-]+$/)
@@ -55,3 +57,13 @@ export const PathnameSchema = Joi.string()
   .message(
     '{{#label}} is not a valid pathname. Pathname should start with slash and not contain any domain or query string.',
   );
+
+export const FrontMatterTagsSchema = JoiFrontMatter.array().items(
+  JoiFrontMatter.alternatives().try(
+    JoiFrontMatter.string().required(),
+    JoiFrontMatter.object<Tag>({
+      label: JoiFrontMatter.string().required(),
+      permalink: JoiFrontMatter.string().required(),
+    }).required(),
+  ),
+);