add contributing and building guidelines

Author: akaszynski

README.rst

@@ -14,3 +14,33 @@ Web-based documentation will be posted upon approval.
 
 PDF version of this guide can be found in the release notes in `Releases
 <https://github.com/pyansys/about/releases>`_.
+
+
+Generate Documentation
+----------------------
+Generate this documentation locally by first installing the
+requirements with:
+
+.. code::
+
+   pip install -r requirements_docs.txt
+
+Then build (on Windows) with:
+
+.. code::
+
+   cd doc
+   make.bat html
+
+Or on Linux with:
+
+.. code::
+
+  make -C doc html
+
+
+Contributing
+------------
+Feel free to contribute to this guide by creating a branch and
+contributing directly, or forking and submitting a PR.  All PRs will
+be reviewed before merge.