message: Add foliage testing instructions
diff: @@ -13,6 +13,7 @@ This is the process we follow when releasing a new version of Cesium for Unreal
  * Does it open without crashing?
  * Does it look correct?
  * Press Play. Does it work as expected? The billboard in each level should give you a good idea of what to expect.
  +* Using one of the sample scenes, open the foliage window and create a new foliage type using any engine static mesh. Verify that foliage painting on Cesium World Terrain works correctly.
  * Test on other platforms if you can. If you can't (e.g., you don't have a Mac), post a message on Slack asking others to give it at least a quick smoke test.
  If all of the above goes well, you're ready to release Cesium for Unreal.
  