Fix 3 typos:
* A repeated word
* Lowercase 'false'
* Lowercase first letter of a sentence
Document parse_partial
Tweak docstrings to match PEP 257
Use str.format to format strings
Fix error message
Fix lowercase 'p' in 'Python'
Fix parser.result() documentation
Emphasize the difference between success() and parser.result()
Rewrite generate() documentation
Provide an expression equivalent to the example function
Add another example function that has no expression equivalent
Merge pull request #1 from bugaevc/docs

Update documentation