first commit based on psycopg2 2.9 version

doc/README.rst

@@ -0,0 +1,20 @@
+How to build psycopg documentation
+----------------------------------
+
+Building the documentation usually requires building the library too for
+introspection, so you will need the same prerequisites_.  The only extra
+prerequisite is virtualenv_: the packages needed to build the docs will be
+installed when building the env.
+
+.. _prerequisites: https://www.psycopg.org/docs/install.html#install-from-source
+.. _virtualenv: https://virtualenv.pypa.io/en/latest/
+
+Build the env once with::
+
+    make env
+
+Then you can build the documentation with::
+
+    make
+
+You should find the rendered documentation in the ``html`` directory.