minirst: remove "admonition" from _admonitions The "admonition" rst primitive is split into "specific" admonitions ("attention," "caution," etc) and the "generic" admonition ("admonition"). For more, see http://docutils.sourceforge.net/docs/ref/rst/directives.html#admonitions The _admonitions set and keys of the _admonitiontitles dict overlap exactly except _admonitions has an "admonition" entry. Nowhere in Mercurial is the "admonition" admonition directive used. Even if it were, it doesn't have a title, so it wouldn't be rendered correctly. So, let's remove "admonition" from the set of recognized admonition directives.