Explicitly add GPL v3 license and release v0.1.0
Update project description

When this library was started, it was only meant for string differences.
However, the functions have since been genericized, so they work on any
types that can be compared!
Add summary documentation comment
Improve documentation strings
Add prettyDiff proc for creating formatted diff
Add example diff application
Add note about adding convenience wrappers
Implement simplediff in Nim along with stringDiff wrapper