add readme info about protobuf styles

README.md

@@ -28,3 +28,17 @@ In `system/include/GL/glfw.h`, replace the wheel callback typedef with
 ```c
 typedef void (GLFWCALL * GLFWmousewheelfun)(float);
 ```
+
+
+
+# Style protobuf
+
+We're encoding the styling information as a protocol buffer, according to
+proto/style.proto. The reason for doing so is that we don't have to ship with a
+JSON/yaml parser. To test the conversion script, run
+
+```
+bin/convert-style.js | protoc --decode=style proto/style.proto
+```
+
+You should see a nicely formatted hierarchical output of the converted style.