Merge pull request #26 from edechter/master

Add info about using GHCi with this package
formatting fixes for README
add `Description :` field for haddock

descriptions are copied from README mostly, but a couple
were missing from there
Add .ghci to repo and suggest the more reliable `cabal repl`
fix help string: there is no run command.
Merge pull request #27 from aavogt/master

documentation update