Add contributing docs

Reviewed By: danielbuechele

Differential Revision: D6976258

fbshipit-source-id: 71b3d0ab4a071ce0c4a9c1241cd6295aa6d52b8e

website/contents/contributing/opening-a-pull-request.md

@@ -4,4 +4,52 @@ title: "Opening a Pull Request"
 hasPlayground: false
 ---
 
-## Opening a Pull Request
+# Opening a Pull Request
+
+Before opening your first pull request to Yoga you have to know how to get the code,
+install build time dependencies, and test the code locally.
+
+### Clone
+
+```
+$> git clone https://github.com/facebook/yoga.git
+$> cd yoga
+```
+
+### Install dependencies
+
+```
+$> git submodule init
+$> git submodule update
+$> brew install buck
+```
+
+### Build and Test
+
+```
+$> buck build //:yoga
+$> buck test //:yoga
+```
+
+## Making a Change
+
+Now all you need to do is make your change and test it before submitting a pull request for review.
+Below is the general structure of the repo and where you may want to make your change. One you have
+made your change see the [testing documentation](/contributing/testing) for more on how to test your change.
+
+``` bash
+/yoga
+|-- yoga                  # Home to the main Yoga codebase written in C++. Any algorithmic changes should be made here
+|-- lib                   # Yoga external dependencies. Be thoughtful adding any new ones
+|-- tests                 # Yoga's C++ test suite. Both manaul and generated tests
+|-- gentest
+|   |-- fixtures          # html fixtures for generated tests    
+|-- java         
+|   |-- com/facebook/yoga # Java binding code
+|   |-- jni               # JNI binding code
+|-- yogacore              # Android bindings without View support
+|-- android               # Android View bindings
+|-- YogaKit               # iOS UIView bindings
+|-- javascript            # emscripten / javascript bindings
+|-- csharp                # .NET bindings in c#
+```