[DOCS] Adds plugin API from 7.16 (#115986)

* [DOCS] Adds 7.16 plugin API changes

* [DOCS] Edits to api changes doc

docs/developer/plugin-api-changes/plugin-api-changes-7_12.asciidoc

@@ -1,14 +1,81 @@
 [[plugin-api-changes]]
-== Plugin API changes in 7.13
+== Plugin API changes in {minor-version}
 ++++
 <titleabbrev>Plugin API changes</titleabbrev>
 ++++
 
 This page discusses the plugin API changes that you need to be aware of when migrating
-your application to {kib} 7.13.
+your application to {kib} {minor-version}.
 
-Other versions: {kibana-ref-all}/7.12/plugin-api-changes.html[7.12] |
+Other versions: {kibana-ref-all}/7.15/plugin-api-changes.html[7.15] |
+{kibana-ref-all}/7.14/plugin-api-changes.html[7.14] |
+{kibana-ref-all}/7.13/plugin-api-changes.html[7.13] |
+{kibana-ref-all}/7.12/plugin-api-changes.html[7.12] |
 {kibana-ref-all}/7.11/plugin-api-changes-7-11.html[7.11] |
 {kibana-ref-all}/7.10/breaking-changes-7.10.html#general-plugin-API-changes-7-10[7.10] |
 {kibana-ref-all}/7.9/breaking-changes-7.9.html#general-plugin-API-changes-79[7.9] |
 {kibana-ref-all}/7.8/breaking-changes-7.8.html#general-plugin-API-changes-78[7.8]
+
+[[breaking_plugin_v7.16.0_112602]]
+.Deprecation warnings logged for plugins that cannot be disabled
+[%collapsible]
+====
+
+The ability for most plugins to be disabled using the `{plugin_name}.enabled`
+config option has been deprecated. In 8.0, most {kib} plugins can no longer
+be disabled using this option.
+
+You can still opt-in to this feature by explicitly adding an
+`enabled` property to your config schema. However, we recommend against
+this when possible. This change affects whether or not a plugin's code is loaded by
+{kib}'s core, introducing complexity and creating a new set of configuration
+scenarios that must be tested.
+
+To allow some aspects of your plugin to be disabled,
+for example the ability to remove it from the {kib} UI,
+we recommend creating "nested" configuration options. For example, use
+`{plugin_name}.ui.enabled` instead of `{plugin_name}.enabled`, and then read
+from the configuration at runtime to conditionally render your application.
+This gives you similar functionality without preventing your plugin code from loading altogether.
+
+Refer to https://github.com/elastic/kibana/pull/112602[#112602].
+
+====
+
+[[breaking_plugin_v7.16.0_109368]]
+.Angular removed from doc viewer
+[%collapsible]
+====
+
+You can no longer use the `directive` property when registering a `DocView` via
+the `addDocView()` method in *Discover* to register an Angular doc view.
+Going forward, we no longer support Angular in our plugin APIs.
+
+Refer to https://github.com/elastic/kibana/pull/109368[#109368].
+
+====
+
+[[breaking_plugin_v7.16.0_109243]]
+.`LegacyRequest` type removed from Core API
+[%collapsible]
+====
+
+The Core API no longer accepts `LegacyRequest` in `BasePath` and `ScopeableRequet` types.
+
+Refer to https://github.com/elastic/kibana/pull/109243[#109243].
+
+====
+
+[[breaking_plugin_v7.16.0_107619]]
+.Legacy {es} client removed
+[%collapsible]
+====
+
+The legacy {es} client is no longer available in `CoreSetup` and
+`RequestHandlerContext` interfaces. Use the
+https://www.elastic.co/guide/en/kibana/current/elasticsearch-service.html[new client]
+instead.
+
+Refer to https://github.com/elastic/kibana/pull/107619[#107619].
+
+====