~/.vimrc: highlight .pxi's with clojure syntax

.vimrc

au BufNewFile,BufRead *.{hs,lhs} set comments=:--,sr:{-,ex:-}
au BufNewFile,BufRead *.rb set comments=:#,s:=begin,e:=end
au BufNewFile,BufRead *.{opa,trx} set filetype=opa shiftwidth=2 tabstop=2 expandtab
au BufNewFile,BufRead *.pxi set filetype=clojure
" Don't let me further than 1 line towards the end or the beginning.
set scrolloff=1