[v10.0.x] Docs: Backport of 69864 - Plugins reorganization (#71100)

* Docs: Plugins doc reorganization, part 1  (#69864)

* Initial commit

* Prettier fixes

* Doc-validator fixes part 1

* Doc-validator fixes part 2

* More doc-validator fixes

* More doc-validator fixes

* Test

* link test

* Linnk test

* Link test

* More fixes

* More fixes

* Doc-validator fixes

* Doc-validator fixes

* fix broken link

* Fix

* Testing

* Doc fixes

* Link fixes

* Fix links

* Update docs/sources/developers/plugins/create-a-grafana-plugin/_index.md

Co-authored-by: David Harris <david.harris@grafana.com>

* Testing

* Testing

* Testing

* Testing

* Doc-validator fixes

* Doc-validator fixes

* Doc-validator fixes

* Fix broken links for plugins reorganization project

* Prettier fixes

* Prettier fixes

* Incorporate reviewer feedback

* Link fixes

* Link fixes

* Link fixes

* Link fix

* Deleted space

* Codeowners fix

* Change grafana.com links to absolute URLs for Hugo

---------

Co-authored-by: David Harris <david.harris@grafana.com>
(cherry picked from commit f9df1f3051)

* Prettier fix

docs/sources/developers/plugins/migration-guide/v7.x-v8.x/_index.md

@@ -1,13 +1,13 @@
 ---
-description: Guide for migrating plugins from Grafana v7.x to v8.x
+title: Migrate plugins from Grafana version 7.x.x to 8.x.x
+menuTitle: v7.x to v8.x
+description: Guide for migrating plugins from Grafana v7.x to v8.x.
 keywords:
   - grafana
   - plugins
   - migration
   - plugin
   - documentation
-title: Migrate plugins from Grafana version 7.x to 8.x
-menutitle: v7.x to v8.x
 weight: 2400
 ---
 
@@ -154,9 +154,9 @@ func (d *SampleDatasource) CheckHealth(_ context.Context, req *backend.CheckHeal
 
 We strongly recommend that you not allow unsigned plugins in your Grafana installation. By allowing unsigned plugins, we can't guarantee the authenticity of the plugin, which could compromise the security of your Grafana installation.
 
-To sign your plugin, see [Sign a plugin](https://grafana.com/docs/grafana/latest/developers/plugins/sign-a-plugin/#sign-a-plugin).
+To sign your plugin, see [Sign a plugin]({{< relref "../../publish-a-plugin/sign-a-plugin.md" >}}).
 
-You can still run and develop an unsigned plugin by running your Grafana instance in [development mode](https://grafana.com/docs/grafana/latest/administration/configuration/#app_mode). Alternatively, you can use the [allow_loading_unsigned_plugins]({{< relref "../../../../setup-grafana/configure-grafana/#allow_loading_unsigned_plugins" >}}) configuration setting.
+You can still run and develop an unsigned plugin by running your Grafana instance in [development mode](/docs/grafana/latest/administration/configuration/#app_mode). Alternatively, you can use the [allow_loading_unsigned_plugins]({{< relref "../../../../setup-grafana/configure-grafana#allow_loading_unsigned_plugins" >}}) configuration setting.
 
 ## Update react-hook-form from v6 to v7
 
@@ -198,7 +198,7 @@ import { cx, css } from '@emotion/css';
 
 ## Update needed for app plugins using dashboards
 
-To make side navigation work properly - app plugins targeting Grafana `8.+` and integrating into the side menu via [addToNav]({{< relref "../../metadata/#properties-4" >}}) property need to adjust their `plugin.json` and all dashboard json files to have a matching `uid`.
+To make side navigation work properly - app plugins targeting Grafana `8.+` and integrating into the side menu via [addToNav]({{< relref "../../metadata#properties-4" >}}) property need to adjust their `plugin.json` and all dashboard json files to have a matching `uid`.
 
 **`plugin.json`**