message: Add link to Nightly builds and build status badge.
diff: Main website: [extraterm.org](http://extraterm.org)
  +[![Build Status](https://dev.azure.com/simon0627/extraterm/_apis/build/status/sedwards2009.extraterm?branchName=master)](https://dev.azure.com/simon0627/extraterm/_build/latest?definitionId=1&branchName=master)
  +
  # About
  Extraterm is an open source project to build a terminal emulator and expand it with new features to support modern workflows and do more than just act like a glorified teletype.
  @@ -53,6 +55,8 @@ See the more detailed [features list](http://extraterm.org/features.html).
  With that out of the way, the primary author does use it as their main terminal emulator on a daily basis. The basics are in place and it will run most common terminal applications such as vi, emacs and joe without problems and even more demanding applications such as midnight commander.
  +Nightly builds of the `master` branch can be [downloaded here](https://storage.googleapis.com/extraterm_builds/index.html).
  +
  # Further Information
  * :loudspeaker: :bird: Follow development on [Twitter @ ExtratermDev](https://twitter.com/ExtratermDev)
  