Update README.md

Fix spelling & add links.
new examples
Revert to d0db918f5a0e6e8d200ea47b0b174cacf5b60f36
Merge pull request #8 from hadley/patch-1

Update README.md
python 3 compatibility
adding better examples
Link to Gohlke's site for unofficial windows binaries of python packages
Merge pull request #11 from yoavram/patch-1

Link to Gohlke's site for unofficial windows binaries of python packages
Merge branch 'master' of github.com:yhat/ggplot