Include Homebrew in installation methods (#681)

Author: jvcarli

README.rst

@@ -13,10 +13,20 @@ available on Leanpub and `Amazon Kindle`_. Read and browse the book for free
 Installation
 ------------
 
+Pip
+^^^
+
 .. code-block:: shell
 
    $ pip install --user tmuxp
 
+Homebrew
+^^^^^^^^
+
+.. code-block:: shell
+
+   $ brew install tmuxp
+
 Load a tmux session
 -------------------
 

docs/quickstart.rst

@@ -21,6 +21,12 @@ You can upgrade to the latest release with:
 
 Then install :ref:`completion`.
 
+If you are a Homebrew user you can install it with:
+
+.. code-block:: bash
+
+    $ brew install tmuxp
+
 CLI
 ---