[v10.0.x] Docs: Remove old plugin docs, fix URLs to go to new dev portal (#75325) (#75718)

* Docs: Remove old plugin docs, fix URLs to go to new dev portal (#75325)

* Remove old plugin docs, add redirects to new dev portal

* Restore plugin.schema.json file

* Update docs/sources/administration/plugin-management/index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* More updates

* Cleanup links

* Update docs/sources/alerting/fundamentals/evaluate-grafana-alerts.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* fix codeowners

* Change reference links to inline links to avoid 404s

* Update docs/sources/datasources/_index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* Update docs/sources/datasources/mysql/_index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* Update docs/sources/datasources/postgres/_index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* Update docs/sources/fundamentals/timeseries-dimensions/index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* Update docs/sources/fundamentals/dashboards-overview/index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* Update docs/sources/fundamentals/dashboards-overview/index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* Update docs/sources/panels-visualizations/configure-standard-options/index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* Update docs/sources/panels-visualizations/query-transform-data/transform-data/index.md

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

* Remove grafana.com from 2 URLs

* Fix 1 more reference link

* Prettier fix

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Co-authored-by: Jack Baldry <jack.baldry@grafana.com>
(cherry picked from commit 0e2b741fc3)
Signed-off-by: Jack Baldry <jack.baldry@grafana.com>

* Fix incorrect content

Co-authored-by: Isabel <76437239+imatwawana@users.noreply.github.com>

* Update docs/sources/alerting/fundamentals/evaluate-grafana-alerts.md

* Update docs/sources/administration/data-source-management/index.md

* Update .changelog-archive/CHANGELOG.7.md

* Update docs/sources/datasources/_index.md

* Update docs/sources/developers/_index.md

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Signed-off-by: Jack Baldry <jack.baldry@grafana.com>
Co-authored-by: Joseph Perez <45749060+josmperez@users.noreply.github.com>
Co-authored-by: Isabel <76437239+imatwawana@users.noreply.github.com>

docs/sources/administration/data-source-management/index.md

@@ -124,7 +124,7 @@ Query caching works for Grafana's [built-in data sources]({{< relref "../../data
 To verify that a data source works with query caching, follow the [instructions below](#enable-and-configure-query-caching) to **Enable and Configure query caching**. If caching is enabled in Grafana but the Caching tab is not visible for the given data source, then query caching is not available for that data source.
 
 {{% admonition type="note" %}}
-Some data sources, such as Elasticsearch, Prometheus, and Loki, cache queries themselves, so Grafana _query_ caching does not significantly improve performance. However, _resource_ caching may help. See the developers page on [plugin resources](/developers/plugin-tools/introduction/backend-plugins#resources) for details.
+Some data sources, such as Elasticsearch, Prometheus, and Loki, cache queries themselves, so Grafana _query_ caching does not significantly improve performance. However, _resource_ caching may help. See the developers page on [plugin resources](/developers/plugin-tools/introduction/backend-plugins) for details.
 {{% /admonition %}}
 
 ### Enable and configure query caching
@@ -195,4 +195,4 @@ For more documentation on a specific data source plugin's features, including it
 
 ### Create a data source plugin
 
-To build your own data source plugin, refer to the ["Build a data source plugin"](/tutorials/build-a-data-source-plugin/) tutorial and our documentation about [building a plugin](/developers/plugins/).
+To build your own data source plugin, refer to the ["Build a data source plugin"](/developers/plugin-tools/tutorials/build-a-data-source-plugin) tutorial and our documentation about [building a plugin](/developers/plugin-tools).