Mercurial's documentation is currently kept in ASCIIDOC format, which
is a simple plain text format that's easy to read and edit. It's also
convertible to a variety of other formats including standard UNIX man
page format and HTML.
To do this, you'll need to install ASCIIDOC:
http://www.methods.co.nz/asciidoc/
To generate the man page:
asciidoc -d manpage -b docbook hg.1.txt
xmlto man hg.1.xml
To display:
groff -mandoc -Tascii hg.1 | more
To create the html page (without stylesheets):
asciidoc -b html4 hg.1.txt
(older asciidoc may want html instead of html4 above)