[feat] docs; update admonition syntax (#68842)

* [feat] docs; update admonition syntax

- Standardizes according to style conventions: https://grafana.com/docs/writers-toolkit/style-guide/style-conventions/#admonitions
- Prepares docs for better, uniform admonition style.

* Remove false positives and irregularities

* false positive removal

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

* Update docs/sources/developers/angular_deprecation/angular-plugins.md

* fix link errors

* Prettify some nested blockquotes

* remoe unnecessary admonition

docs/sources/developers/http_api/licensing.md

@@ -61,7 +61,9 @@ Status codes:
 
 ## Add license
 
-> **Note:** Available in Grafana Enterprise v7.4+.
+{{% admonition type="note" %}}
+Available in Grafana Enterprise v7.4+.
+{{% /admonition %}}
 
 `POST /api/licensing/token`
 
@@ -121,7 +123,9 @@ Status Codes:
 
 ## Manually force license refresh
 
-> **Note:** Available in Grafana Enterprise v7.4+.
+{{% admonition type="note" %}}
+Available in Grafana Enterprise v7.4+.
+{{% /admonition %}}
 
 `POST /api/licensing/token/renew`
 
@@ -180,7 +184,9 @@ Status Codes:
 
 ## Remove license from database
 
-> **Note:** Available in Grafana Enterprise v7.4+.
+{{% admonition type="note" %}}
+Available in Grafana Enterprise v7.4+.
+{{% /admonition %}}
 
 `DELETE /api/licensing/token`