[v10.0.x] [feat] docs; update admonition syntax (#68857)

[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

(cherry picked from commit 1c4bb9ca00)

Co-authored-by: Matt Dodson <47385188+MattDodsonEnglish@users.noreply.github.com>

docs/sources/developers/http_api/alerting.md

@@ -15,7 +15,9 @@ title: 'Alerting HTTP API '
 
 # Legacy Alerting API
 
-> **Note:** Starting with v9.0, the Legacy Alerting HTTP API is deprecated. It will be removed in a future release.
+{{% admonition type="note" %}}
+Starting with v9.0, the Legacy Alerting HTTP API is deprecated. It will be removed in a future release.
+{{% /admonition %}}
 
 This topic is relevant for the [legacy dashboard alerts](https://grafana.com/docs/grafana/v8.5/alerting/old-alerting/) only.