Added README.md and .gitignore

It's a good practice to keep a README. By default github recognizes README.md and shows it under your repository's web page. It has a specific format, look it up.

.gitignore file is very useful in git projects. It won't allow files that you choose enter your repository and therefore fill it with garbage. As an exampled I added *.pyc in it, so that each time you run your program and these files are produced they don't get added to the repository. Add files you don't want "tracked" by git to this file.