Docs: Add CONTRIBUTING.md to docs build

Adds CONTRIBUTING.md to the docs build, and moves some
contribution-related content from getting_started.md to CONTRIBUTING.md.

Bug: 161

Change-Id: Ie5b15252eb544cbc3c42e5a0cea78ce8fe2f9f63
diff --git a/docs/BUILD.gn b/docs/BUILD.gn
index 4fa235d..3b5162b 100644
--- a/docs/BUILD.gn
+++ b/docs/BUILD.gn
@@ -41,6 +41,7 @@
   conf = "conf.py"
   sources = [
     "../CODE_OF_CONDUCT.md",
+    "../CONTRIBUTING.md",
     "../README.md",
     "index.rst",
     "modules.rst",
diff --git a/docs/getting_started.md b/docs/getting_started.md
index 8a1a0ad..57e71a8 100644
--- a/docs/getting_started.md
+++ b/docs/getting_started.md
@@ -1,16 +1,17 @@
 # Getting started
 
-## Initial Setup
-
 Pigweed uses a combination of CIPD and Python virtual environments to provide
 you with the tools necessary for Pigweed development without modifying your
 system's development environment. This guide will walk you through the steps
 needed to download and set up the Pigweed repository.
 
+After the initial setup, this guide will walk you through a few things to try
+out to familiarize you with the Pigweed codebase and developer workflow.
+
 We hope to make the setup process as smooth as possible. If any of this doesn't
 work, please [file a bug](https://bugs.chromium.org/p/pigweed/issues/entry).
 
-### Prerequisites
+## Prerequisites
 
 **Linux**<br/>
 Linux should work out of box, and not require any manual installation of
@@ -36,10 +37,14 @@
 above). We recommend you install Git to run from the command line and third
 party software.
 
-### Setup
+If you plan to flash devices with firmware, you'll need to install OpenOCD and
+ensure it's on your system path.
 
-Once you have prerequisites satisfied, you should be able to clone Pigweed and
-run the bootstrap that initializes the Pigweed virtual environment.
+## Bootstrap
+
+Once you satisfied the prerequisites, you should be able to clone Pigweed and
+run the bootstrap that initializes the Pigweed virtual environment. The
+bootstrap may take several minutes to complete, so please be patient.
 
 **Linux/macOS**
 ```bash
@@ -58,43 +63,15 @@
 
 Below is a real-time demo with roughly what you should expect to see as output:
 
+![build example using pw watch](images/pw_env_setup_demo.gif)
 
-### Contributors
-
-If you plan to contribute to Pigweed, you'll need to set up a commit hook for
-Gerrit.
-
-**Linux/macOS**<br/>
-```bash
-$ f=`git rev-parse --git-dir`/hooks/commit-msg ; mkdir -p $(dirname $f) ; curl -Lo $f https://gerrit-review.googlesource.com/tools/hooks/commit-msg ; chmod +x $f
-```
-
-**Windows**<br/>
-Download [the Gerrit commit hook](https://gerrit-review.googlesource.com/tools/hooks/commit-msg)
-and then copy it to the `.git\hooks` directory in the Pigweed repository.
-```batch
-copy %HOMEPATH%\Downloads\commit-msg %HOMEPATH%\pigweed\.git\hooks\commit-msg
-```
-
-All Pigweed CLs must adhere to Pigweed's style guide and pass automated builds,
-tests, and style checks to be merged upstream. Much of this checking is done
-using Pigweed's pw_presubmit module. To speed up the review process, consider
-adding `pw presubmit` as a git push hook using the following command:
-
-**Linux/macOS**<br/>
-```bash
-$ pw presubmit --install
-```
-
-### Congratulations!
-
-You are now set up to start using Pigweed!
+Congratulations, you are now set up to start using Pigweed!
 
 ## Pigweed Environment
 
 After going through the initial setup process, your current terminal will be in
 the Pigweed development environment that provides all the tools you should need
-to develop on Pigweed. If leave that session, you can activate the
+to develop on Pigweed. If you leave that session, you can activate the
 environment in a new session with the following command:
 
 **Linux/macOS**
diff --git a/docs/index.rst b/docs/index.rst
index 3139e46..c42abc8 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -10,6 +10,7 @@
 
   Home <self>
   CODE_OF_CONDUCT.md
+  CONTRIBUTING.md
   docs/getting_started.md
   docs/embedded_cpp_guide
   docs/style_guide