area/configuration: adds docs for actions_allow_post_url security option (#93629)

adds docs for actions_allow_post_url security option

docs/sources/setup-grafana/configure-grafana/_index.md

@@ -701,6 +701,18 @@ You can enable both policies simultaneously.
 
 Set the policy template that will be used when adding the `Content-Security-Policy-Report-Only` header to your requests. `$NONCE` in the template includes a random nonce.
 
+### actions_allow_post_url
+
+Sets API paths to be accessible between plugins using the POST verb. This is a comma separated list, and uses glob matching.
+
+This will allow access to all plugins that have a backend:
+
+`actions_allow_post_url=/api/plugins/*`
+
+This will limit access to the backend of a single plugin:
+
+`actions_allow_post_url=/api/plugins/grafana-special-app`
+
 <hr />
 
 ### angular_support_enabled