Update CONTRIBUTING.rst

Added NetworkX to the pre-approved list of libraries, per https://github.com/epimodels/Zeke/issues/7
MathJax

***NOT CURRENTLY WORKING *** Attempting to enable MathJax via
Django-Mathjax. At present, the application should be enabled and
usable, but something isn’t loading correctly.
Formatted Contacts

Got rid of the obfuscated email address, and have put in example
MathJax activation scripts in contact.html, but there is no MathJax
content for the moment - it’s just enabled.
Merge pull request #9 from epimodels/MathJax

MathJax
Text to MathJax

Converting text-based greek notation to MathJax
Merge branch 'MathJax-Cleanup'
Merge pull request #10 from epimodels/MathJax-Cleanup

Text to MathJax
Button fix

Lost a button, fixed.
Merge branch 'master' of https://github.com/epimodels/Zeke