help: better explanation for some of the environment variables
In particular, the precedence for usernames is explained in more detail.
Thanks to timeless for pointing out the deficiencies here.
[hooks]
pretxncommit.cr = python:hgext.win32text.forbidcr
pretxnchangegroup.cr = python:hgext.win32text.forbidcr
Attempt to commit or push text file(s) using CR line endings
in dea860dc51ec: f
transaction abort!
rollback completed
abort: pretxncommit.cr hook failed
hello<LF>
hello<CR>