Add levenshtein_ratio function. Add maximum inline function for use in levenshtein_ratio.
Update README and installation instructions to include ratio function.
max for only 2 parameters
made levenshtein_ratio return double && avoid division by 0 if lengths n&m are both 0
math.h library not needed after deleting llround conversion
revised author credits
unittest
ignore compiled libraries
Made README as markdown and updated info