Gitignore and README

The project had no .gitignore because we recently  moved it to git. The
most popular format for the README is markdown, so I reformatted the file.

The info contained in the readme is way out of date and needs to be updated, and I 
at least fixed what's currently displaying on the github plugins page,
but I have to commit the .gitignore before I create a project in my IDE. It also makes
sense at this point that I make this commit so the .gitignore makes it to master as soon
as possible.