This is the usual practice in MediaWiki and extensions,
for consistency among wikis where pages
are not necessarily articles.
Change-Id: I245b9c79e5de55c2c581f53fb4ae0890c4ff4119
Long-term todo:
* Performance will be poor on large pages due
to using a auto-height textarea which CodeMirror
doesn't optimise.
Change-Id: I16598fcdbeee51e6fae88376ec81f1c8552b383d
Use a message, that explains a bit more, what CodeMirror is and indicate
what the button do exactly.
Change-Id: If8a0a8261cd811407cff4868dcf6475335b3f752
