Add a quickstart tutorial & re-organize index page

We split docs into tutorials & more in-depth guides.

docs/guides/install.rst

@@ -0,0 +1,42 @@
+.. _installation:
+
+Installation
+============
+
+Quick Installation
+------------------
+
+The quick way to install The Littlest JupyterHub (tljh) is:
+
+.. code-block:: bash
+
+   curl https://raw.githubusercontent.com/yuvipanda/the-littlest-jupyterhub/master/installer/install.bash | sudo bash -
+
+This takes 2-5 minutes to run. When completed, you can access your new JupyterHub
+at the public IP of your server!
+
+You should probably add yourself as an `admin user <admin.md>`_
+after installation.
+
+Slightly less quick installation
+--------------------------------
+
+If you can read ``bash`` and are nervous about the previous installation method,
+you can inspect the installer script before running it.
+
+
+1. Download the installer script
+
+   .. code-block:: bash
+
+      curl https://raw.githubusercontent.com/yuvipanda/the-littlest-jupyterhub/master/installer/install.bash  -o install.bash
+
+2. Read the install script source using your favorite text editor
+
+3. Run the installer script
+
+   .. code-block:: bash
+
+      sudo install.bash
+
+   This should have the exact same effects as the quick installer method.