Add link to the proposed wrapper generation patch

[ikiwiki] / doc / bugs / comments_preview_unsafe_with_allowdirectives.mdwn

If `comments_allowdirectives` is set, previewing a comment can run
directives that create files. (Eg, img.) Unlike editpage, it does not
keep track of those files and expire them. So the files will linger in
destdir forever.

Probably when the user then tries to save the comment, ikiwiki will refuse
to overwrite the unknown file, and will crash.
--[[Joey]]