message: Added medium post and github links to posenet website.
diff: _PoseNet_ is a vision model that can be used to estimate the pose of a person in
  an image or video by estimating where key body joints are.
  -<a class="button button-primary" href="https://storage.googleapis.com/download.tensorflow.org/models/tflite/posenet_mobilenet_v1_100_513x513_multi_kpt_stripped.tflite">
  +<a class="button button-primary" href="https://storage.googleapis.com/download.tensorflow.org/models/tflite/posenet_mobilenet_v1_100_257x257_multi_kpt_stripped.tflite">
  Download starter model</a>
  Android and iOS end-to-end tutorials are coming soon. In the meantime, if you
  @@ -146,6 +146,7 @@ is faster but results in lower accuracy.
  <ul>
  <li><a href="https://medium.com/tensorflow/real-time-human-pose-estimation-in-the-browser-with-tensorflow-js-7dd0bc881cd5">Blog post: Real-time Human Pose Estimation in the Browser with TensorFlow.js</a></li>
  <li><a href="https://github.com/tensorflow/tfjs-models/tree/master/posenet">TF.js GitHub: Pose Detection in the Browser: PoseNet Model</a></li>
  + <li><a href="https://medium.com/tensorflow/track-human-poses-in-real-time-on-android-with-tensorflow-lite-e66d0f3e6f9e">Blog post: Track human poses in real-time on Android with TensorFlow Lite</a></li>
  </ul>
  ### Use cases
  