Add more explanation to Twisted section.

Author: pya

twisted.rst

@@ -2,25 +2,39 @@
 Learn asyncio if you come from Twisted
 ++++++++++++++++++++++++++++++++++++++
 
-`Twisted project <https://twistedmatrix.com/trac/>`_.
+The `Twisted project <https://twistedmatrix.com/trac/>`_ is probably one of the
+oldest libraries that supports asynchronous programming in Python.
+It has been used by many programmers to develop a variety of applications.
+It supports many network protocols and can be used for many different
+types of network programming.
+In fact, asyncio was heavily inspired by Twisted.
+The expertise of several Twisted developers had been incorporated in
+asyncio.
+Soon, there will be a version of Twisted that is based on asyncio.
+
 
 
 Rosetta Stone
 =============
 
+This tables shows equivalent concepts in Twisted and asyncio.
+
 ========================  ==================================
 Twisted                   asyncio
 ========================  ==================================
-Deferred                  asyncio.Future
-deferToThread(func)       loop.run_in_executor(None, func)
-@inlineCallbacks          async def
-reactor.run()             loop.run_forever()
+``Deferred``              ``asyncio.Future``
+``deferToThread(func)``   ``loop.run_in_executor(None, func)``
+``@inlineCallbacks``      ``async def``
+``reactor.run()``         ``loop.run_forever()``
 ========================  ==================================
 
 
 Deferred example
 ================
 
+This small example shows two equivalent programs, one implemented in Twisted
+and one in asyncio.
+
 +--------------------------------------------------+--------------------------------------------------+
 | Twisted                                          | asyncio                                          |
 +==================================================+==================================================+