Add create-nightwatch docs.

guide/getting-started/onboarding-cli.md

@@ -0,0 +1,34 @@
+## Nightwatch Onboarding CLI
+
+#### Overview
+
+This CLI tool lets you setup Nightwatch.js in your new or existing project, with all the required configs and dependencies, with just one command.
+
+#### Usage
+
+All you need to do is, run:
+
+##### 1) If you're in your existing project's root directory:
+
+<pre><code class="language-bash">npm init nightwatch</code></pre>
+
+##### 2) If you want to create a new project:
+
+<pre><code class="language-bash">npm init nightwatch path/to/new/project</code></pre>
+
+and answer a few questons. We'll setup everything for you based on your preferences.
+
+
+If you'd like to skip all the questions (we'd assume best defualts for you), you can use the above commands with `--yes` or `-y` flag:
+
+##### 1) If you're in your existing project's root directory:
+
+<pre><code class="language-bash">npm init nightwatch -- --yes
+# or
+npm init nightwatch -- -y</code></pre>
+
+##### 2) If you want to create a new project:
+
+<pre><code class="language-bash">npm init nightwatch path/to/new/project -- --yes
+# or
+npm init nightwatch path/to/new/project -- -y</code></pre>