Change Details

@MSchottlender-WMF had a great idea: we should build a demo page for notifications, similar to the OOUI widgets demo, based on the new widgets planned in T115419. This demo should exercise all the different options that the widgets provide for. Additionally (or separately), it would also be great to have a demo that shows examples of all notification types in existence; this might be tricky to generate automatically, but we could always hand-code the demo data to start with.