Update README with more details

Author: 1st1

README.rst

@@ -11,15 +11,36 @@ module (see PEP 567) for Python 3.6.
 **Important:** at this moment this package does not provide an
 asyncio event loop with PEP 567 support yet.  Stay tuned for updates.
 
-Documentation: https://docs.python.org/3.7/library/contextvars.html
 
-Usage:
+Documentation
+=============
+
+Read the official ``contextvars`` module documentation here:
+https://docs.python.org/3.7/library/contextvars.html
+
+
+`PEP 567 <https://www.python.org/dev/peps/pep-0567/>`_ also provides
+a comprehensive overview of the API and explains the design choices.
+
+
+Installation
+============
+
+.. code-block:: bash
+
+    $ pip install pep567
+
+
+Usage
+=====
 
 .. code-block:: python
 
     try:
+        # Python 3.7
         import contextvars
     except ImportError:
+        # Python <= 3.6
         import pep567 as contextvars
 
     my_var = contextvars.ContextVar('my_var')