* Point to irc.freenode.net instead of irc.atheme.org. I know that it's
CNAME to chat, but I think it's preferable to use the irc. subdomain
to make it clear that it's IRC.
* Point to GitHub issue tracker instead of bugs-meta.atheme.org that
doesn't exist
* Remove mentioning of BUGS file and change README.FIRST to README.md as
the first doesn't exist and I think they are the same file.