doc: translate from :hg:`help config.SECTION` to a valid link to hgrc.5.html...
doc: translate from :hg:`help config.SECTION` to a valid link to hgrc.5.html
Before this patch, ":hg:`help config.SECTION`" in online help text is
translated to a link to "hg.1.html#config.SECTION" in HTML
unintentionally.
This patch translates from :hg:`help config.SECTION` in online help
text to a valid link to "hgrc.5.html#SECTION" in HTML.
This patch ignores element(s) under "SECTION" (e.g. "ITEM" of
":hg:`help config.SECTION.ITEM`"), because there is no way to refer
directly to it in HTML, yet.