hgrc.5: drop 'hgext.' prefix when talking about extensions
The first paragraph apply to all extensions, not just those in hgext.
The second paragraph can just use the simpler form to load mq.
Test the GPG extension
$ "$TESTDIR/hghave" gpg || exit 80
$ cat <<EOF >> $HGRCPATH
> [extensions]
> gpg=
>
> [gpg]
> cmd=gpg --no-permission-warning --no-secmem-warning --homedir $TESTDIR/gpg
> EOF
$ hg init r
$ cd r
$ echo foo > foo
$ hg ci -Amfoo
adding foo
$ hg sigs
$ hg sign 0
Signing 0:e63c23eaa88a
$ hg sigs
hgtest 0:e63c23eaa88ae77967edcf4ea194d31167c478b0
$ hg sigcheck 0
e63c23eaa88a is signed by:
hgtest