It still deals with Emacs 21 issues. Especially most UTF-8 things are no longer relevant in recent Emacs versions. I'll prepare a patch.
Created attachment 354656 [details, diff] [PATCH 1/3] appendices/editor-configuration/emacs: Use <c> tags where appropriate.
Created attachment 354658 [details, diff] [PATCH 2/3] appendices/editor-configuration/emacs: Update weblinks.
Created attachment 354660 [details, diff] [PATCH 3/3] appendices/editor-configuration/emacs: Delete outdated information.
I can push these myself if approved.
Pushed.