[Monitoring] Add breaking change for constants change (elastic#30710)

* Add breaking change for constants change

* PR feedback

* [DOCS] Edits the new breaking changes

* [DOCS] Reverts merge

* Removes yarn.lock from PR

* Removes accidental files from PR

* [DOCS] Adds settings section to Breaking changes (elastic#30757)

* [DOCS] Edits the new breaking changes

docs/migration/migrate_7_0.asciidoc

@@ -284,6 +284,30 @@ file have been removed.
 
 *Impact:* Use `xpack.upgrade_assistant.<any setting>` instead.
 
+[float]
+==== `xpack.monitoring.beats.index_pattern` is no longer valid
+
+*Details:* The unsupported `xpack.monitoring.beats.index_pattern` setting in the
+`kibana.yml` file has been officially removed.
+
+*Impact:* The ability to customize this pattern is no longer supported.
+
+[float]
+==== `xpack.monitoring.cluster_alerts.index` is no longer valid
+
+*Details:* The unsupported `xpack.monitoring.cluster_alerts.index` setting in
+the `kibana.yml` file has been officially removed. 
+
+*Impact:* The ability to customize this index is no longer supported.
+
+[float]
+==== `xpack.monitoring.elasticsearch.index_pattern` is no longer valid
+
+*Details:* The unsupported `xpack.monitoring.elasticsearch.index_pattern`
+setting in the `kibana.yml` file has been officially removed.
+
+*Impact:* The ability to customize this pattern is no longer supported.
+
 [float]
 ==== `xpack.monitoring.elasticsearch.ssl.ca` is no longer valid
 
@@ -323,6 +347,30 @@ is protocol dependent: https ports will use 443, and http ports will use 80. If
 `xpack.monitoring.elasticsearch.url` was dependent on an unspecified port set to
 9200, append `:9200` to the url in `xpack.monitoring.elasticsearch.hosts`.
 
+[float]
+==== `xpack.monitoring.index_pattern` is no longer valid
+
+*Details:* The unsupported `xpack.monitoring.index_pattern` setting in the
+`kibana.yml` file has been officially removed.
+
+*Impact:* The ability to customize this pattern is no longer supported.
+
+[float]
+==== `xpack.monitoring.kibana.index_pattern` is no longer valid
+
+*Details:* The unsupported `xpack.monitoring.kibana.index_pattern` setting in
+the `kibana.yml` file has been officially removed.
+
+*Impact:* The ability to customize this pattern is no longer supported.
+
+[float]
+==== `xpack.monitoring.logstash.index_pattern` is no longer valid
+
+*Details:* The unsupported `xpack.monitoring.logstash.index_pattern` setting in
+the `kibana.yml` file has been officially removed.
+
+*Impact:* The ability to customize this pattern is no longer supported.
+
 [float]
 ==== `xpack.monitoring.node_resolver` is no longer valid