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>

docs/sources/developers/plugins/introduction-to-plugin-development/_index.md

@@ -1,13 +1,21 @@
 ---
-description: Conceptual topics for plugin development
-title: Introduction to plugin development
+title: Introduction to Grafana plugin development
+menuTitle: Introduction to plugin development
+keywords:
+  - grafana
+  - plugins
+  - plugin
+  - documentation
+description: Conceptual topics for Grafana plugin development.
+weight: 100
 ---
 
 # Introduction to Grafana plugin development
 
-This section contains topics related to the key concepts for Grafana plugin development.
+This section contains documentation related to the key concepts for Grafana plugin development.
 
-- [Backend plugins]({{< relref "../backend/" >}})
-  - [Grafana plugin SDK for Go]({{< relref "../backend/grafana-plugin-sdk-for-go.md" >}})
-  - [Plugin protocol]({{< relref "../backend/plugin-protocol.md" >}})
-- [Data frames]({{< relref "data-frames.md">}})
+- [Backend plugins]({{< relref "./backend" >}})
+  - [Grafana plugin SDK for Go]({{< relref "./backend/grafana-plugin-sdk-for-go.md" >}})
+  - [Plugin protocol]({{< relref "./backend/plugin-protocol.md" >}})
+- [Data frames]({{< relref "./data-frames.md" >}})
+- [Error handling]({{< relref "./error-handling.md" >}})