Link to readme from description

If you are viewing a repository for the first time you are likely to view the description. If you want to keep reading after that you can now click a link to the readme. This place is in addition to the README button at the bottom of the right hand menu that is harder to find. If you have edit rights only the description edit button is shown to ensure the text fits, the assumption is that the readme is most interesting for people not yet added to the project.