Show autocomplete list when editing notes.

app/assets/javascripts/notes.js

@@ -227,10 +227,11 @@ var NoteList = {
     // Show the attachment delete link
     note.find(".js-note-attachment-delete").show();
 
+    GitLab.GfmAutoComplete.setup();
+
     var form = note.find(".note-edit-form");
     form.show();
 
-
     var textarea = form.find("textarea");
     var p = $("<p></p>").text(textarea.val());
     var hidden_div = $('<div class="note-original-content"></div>').append(p);