Update irc.md
Update irc.md

added #haskell.vn vietnamese speakers IRC channel on freenode
haskell-infra/hl,josefs/hl,haskell-lang/haskell-lang,haskell-infra/hl,gbaz/hl,commercialhaskell/commercialhaskell.com,erantapaa/hl,erantapaa/hl,gbaz/hl,imalsogreg/hl,commercialhaskell/commercialhaskell.com,imalsogreg/hl,erantapaa/hl,commercialhaskell/commercialhaskell.com,kxxoling/hl,bitemyapp/commercialhaskell.com,kxxoling/hl,snoyberg/hl,snoyberg/hl,bitemyapp/commercialhaskell.com,haskell-lang/haskell-lang,kxxoling/hl,josefs/hl,imalsogreg/hl,haskell-lang/haskell-lang,gbaz/hl,haskell-infra/hl,bitemyapp/commercialhaskell.com,josefs/hl,snoyberg/hl