Update Fixed.hs

The example in the documentation of fLit contains an error. The number '2.2867' does not correpond to 'Integer 45' (which leads indeed to '2.8125'), but it corresponds to 'Integer 36' (which leads to '2.25').

There are several ways to fix this, I decided to move the second '2' in '2.2867' to the end.
Merge pull request #6 from EagleErwin/patch-1

Fixed error on documentation of fLit in Fixed.hs