Use sphinx for generating documentation

This adds sphinx based documentation generation.  For now,
this manily renders some introduction and the autodoc-genreated
class/method reference from the source code for our libraries.

Actual user-level documentation for pySim-{prog,shell,read} remains
to be added separately

Change-Id: I52603e93c2c129a9e79687da6c534fa56a40a649

docs/index.rst

@@ -0,0 +1,50 @@
+.. pysim documentation master file
+
+Welcome to Osmocom pySim
+========================
+
+Introduction
+------------
+
+pySim is a python implementation of various software that helps you with
+managing subscriber identity cards for cellular networks, so-called SIM
+cards.
+
+Many Osmocom (Open Source Mobile Communications) projects relate to operating
+private / custom cellular networks, and provisioning SIM cards for said networks
+is in many cases a requirement to operate such networks.
+
+To make use of most of pySim's features, you will need a `programmable` SIM card,
+i.e. a card where you are the owner/operator and have sufficient credentials (such
+as the `ADM PIN`) in order to write to many if not most of the files on the card.
+
+Such cards are, for example, available from sysmocom, a major contributor to pySim.
+See https://www.sysmocom.de/products/lab/sysmousim/ for more details.
+
+pySim supports classic GSM SIM cards as well as ETSI UICC with 3GPP USIM and ISIM
+applications.  It is easily extensible, so support for additional files, card
+applications, etc. can be added easily by any python developer.  We do encourage you
+to submit your contributions to help this collaborative development project.
+
+pySim consists of several parts:
+
+* a python :ref:`library<pySim library>` containing plenty of objects and methods that can be used for
+  writing custom programs interfacing with SIM cards.
+* the [new] :ref:`interactive pySim-shell command line program<pySim-shell>`
+* the [legacy] :ref:`pySim-prog and pySim-read tools<Legacy tools>`
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contents:
+
+   shell
+   legacy
+   library
+
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`