Change plugin templates

This PR changes the following:

- Change the wording for non default plugin
- Add a link to a help section

Fixes #6719

tools/logstash-docgen/templates/plugin-doc.asciidoc.erb

@@ -6,9 +6,18 @@
 * <%=changelog_url%>[Changelog]
 
 <% unless default_plugin? %>
-NOTE: This plugin does not ship with Logstash by default, but it is easy to install by running `bin/logstash-plugin install logstash-<%= section %>-<%= name %>`.
+==== Installation
+
+For plugins not bundled by default, it is easy to install by running `bin/logstash-plugin install logstash-<%= section %>-<%= name %>`. See <<working-with-plugins>> for more details.
 <% end %>
 
+==== Getting Help
+
+For questions about the plugin, open a topic in the http://discuss.elastic.co[Discuss] forums. For bugs or feature requests, open an issue in https://github.com/elastic/logstash[Github].
+For the list of Elastic supported plugins, please consult the https://www.elastic.co/support/matrix#show_logstash_plugins[Elastic Support Matrix].
+
+=== Description
+
 <%= description %>
 
 &nbsp;