CodeMirror was updated to 5.6. This one includes a new dark theme abcdef.

There are also new addons that I have not included but might be useful.

autorefresh

Deals with the known issue that CodeMirror doesn't render correctly if initially loaded in a hidden part of the page. The Joomla plugin is already dealing with this issue by calling CodeMirror's refresh function whenever one of the shown events is fired so this is not really an issue when using CodeMirror in Joomla. However, this solution only works for specific events (basically, Bootstrap's various shown events) and also uses jQuery. The new addon would solve this issue by polling the editor until it's visible and then refreshing it. This solution will work even if jQuery is not available or Bootstrap is not the reason that the editor was hidden in the first place.

html-lint

Uses HTMLHint to find mistakes in your html code. Personally, I'm a big fan of live-linting. I think this should be included.

Any opinions about either of these addons? I'm most likely going to add them to this PR in the near future unless there is any objection.