doc: use "tag" revset predicate instead of "tagged" for example in help
"tag" predicate is officially described in help, but "tagged" is not,
even though the latter works as same as the former.
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing:
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.