Supporting haskell execution

[feature-not-a-bug]

I was hoping to get Haskell support for running interpreted code using the runhaskell utility. Test code:

fibs :: [Int]
fibs = 0 : 1 : zipWith (+) fibs (tail fibs)

main = putStrLn $ show $ take 10 fibs

The usual usage in a presentation would be to have warnings suppressed with the -w flag, although having some ability to customize this could be useful

$  runhaskell -w test.hs
[0,1,1,2,3,5,8,13,21,34]

[mfontanini]

Could you create a PR changing this file accordingly? You should have a new entry for haskell with the right commands. e.g. see https://github.com/mfontanini/presenterm/pull/399/files for an example.

[feature-not-a-bug]

Just created #414