Add plugin stability badges (#8198)

* Initial Commit

* Fix plugin library URL

* Need to set plugin library location for prerelease

* Styling tweaks

* Docs

* Add tests that the core plugins all have a valid stability field

plugins/tiddlywiki/mobiledragdrop/plugin.info

@@ -3,5 +3,6 @@
 	"name": "Mobile Drag Drop",
 	"description": "Mobile drag and drop shim",
 	"author": "Tim Ruffles",
-	"list": "readme license"
+	"list": "readme license",
+	"stability": "STABILITY_0_DEPRECATED"
 }