Fix general spelling, grammar, and formatting errors in README.md

Before:

![screen shot 2014-05-27 at 5 13 32 pm](https://cloud.githubusercontent.com/assets/4745181/3099463/fbc5fd14-e5fc-11e3-9173-6052ea7d99c2.png)

![screen shot 2014-05-27 at 5 13 37 pm](https://cloud.githubusercontent.com/assets/4745181/3099464/0101173c-e5fd-11e3-98bc-ea13e8949897.png)

After:

![screen shot 2014-05-27 at 5 15 44 pm](https://cloud.githubusercontent.com/assets/4745181/3099472/3eb1f092-e5fd-11e3-94a9-cf24445109d5.png)

![screen shot 2014-05-27 at 5 16 10 pm](https://cloud.githubusercontent.com/assets/4745181/3099474/4900c730-e5fd-11e3-9e81-f67f4d0c084c.png)

Besides that there are just a few spelling fixes and grammar changes, e.g. deleguates -> delegates and the like.