Browser dropdown pull request

Adding changes mentioned (in Readme.md and removing .gitignore)
Double check the README.md. It already has "activator run".
Code should be marked with ``` not ´´´. Moreover, you can specify which language it uses so that it's rendered correctly. Something like ```bash or ```java.
Code should be written in a way that can be copy/pasted. "activator run / sbt run" should not work