Docs: Update RenderCommand.tid (#3263)

Adds a link that opens the advanced search with a filter to list all the template tiddlers.

editions/tw5.com/tiddlers/commands/RenderCommand.tid

@@ -6,3 +6,10 @@ title: RenderCommand
 type: text/vnd.tiddlywiki
 
 {{$:/language/Help/render}}
+
+<$button class="tc-btn-invisible" style="text-decoration:underline">
+Show available rendering templates
+<$action-setfield $tiddler="$:/temp/advancedsearch" text="[all[shadows]prefix[$:/core/templates/]]"/>
+<$action-setfield $tiddler="$:/state/tab--1498284803" text="$:/core/ui/AdvancedSearch/Filter"/>
+<$action-navigate $to="$:/AdvancedSearch"/>
+</$button>