Create Style Guide for UNTL Metadata Docs

[vphill]

Here are a few examples just for reference.

• https://documentation-style-guide-sphinx.readthedocs.io/en/latest/style-guide.html
• https://docs.pylonsproject.org/projects/docs-style-guide/
• https://docs.djangoproject.com/en/dev/internals/contributing/writing-documentation/

[vphill]

I have been using this heirarchy from the documentation-style-guide-sphinx documentation above.

##################
H1: document title
##################

Introduction text.

*********
Sample H2
*********

Sample content.

**********
Another H2
**********

Sample H3
=========

Sample H4
---------

Sample H5
^^^^^^^^^

Sample H6
"""""""""

And some text.