Fixed some formatting and grammatical errors.

This is my first github pull request, so please bear with me if I'm not using the correct procedure. 

This documentation page had a few of problems. Some formatting that was not kramdown (maybe left over from a previous system?) and it was causing odd characters to show up, or words to disappear and leave sentences incomprehensible.  I also fixed some references to the "class `html`" when really the class is called `HTML`.