Documentation improvements

CONTRIBUTING.md

@@ -49,3 +49,18 @@ The Sky engine repository gladly accepts contributions via GitHub pull requests:
  * `git push origin name_of_your_branch`
  * Go to `https://github.com/<your_name_here>/sky_engine` and click the
    "Compare & pull request" button
+
+You must complete the
+[Contributor License Agreement](https://cla.developers.google.com/clas).
+You can do this online, and it only takes a minute.
+If you've never submitted code before, you must add your (or your
+organization's) name and contact info to the [AUTHORS](AUTHORS) file.
+
+Running tests
+-------------
+
+Tests are only supported on Linux currently.
+
+ * ``sky/tools/test_sky --debug``
+   * This runs the tests against ``//out/Debug``. If you want to run against
+     ``//out/Release``, omit the ``--debug`` flag.

README.md

@@ -1,2 +1,14 @@
 Sky
 ===
+
+Sky is a new way to build high performance, cross platform mobile apps.
+More specifically, Sky is a rendering engine, a scripting engine, an
+(optional) framework, and a (optional) set of Material Design widgets.
+Sky is optimized for today's, and tomorrow's, mobile devices. We are focused
+on low-latency input, high frame rates, and we are purely mobile first.
+
+For information about using our latest stable release of Sky, please
+see the [Sky SDK](https://github.com/domokit/sky_sdk/) project page.
+
+For information about contributing to Sky, please see
+[CONTRIBUTING.md](CONTRIBUTING.md).