docs: adjust install instructions to remove git method

It seems installing via the git method doesn't actually do anything differently. Potentially related issue:

pypa/pip#5780

Author: jtpavlock

docs/getting_started.rst

@@ -5,23 +5,17 @@ Getting Started
 ************
 Installation
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-1a. The latest release of Moe is available on `PyPI <https://pypi.org/project/moe>`_
+#. The latest release of Moe is available on `PyPI <https://pypi.org/project/moe>`_
 
-.. code-block:: bash
-
-    $ pip install moe
-
-1b. Or, if you want to be on the bleeding edge and can't wait for the latest release, you can install from github.
+   .. code-block:: bash
 
-.. code-block:: bash
-
-    $ pip install git+https://github.com/MoeMusic/Moe@master
+       $ pip install moe
 
-2. Ensure everything is working properly.
+#. Ensure everything is working properly.
 
-.. code-block:: bash
+   .. code-block:: bash
 
-    $ moe --version
+       $ moe --version
 
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 Understanding Plugins