Create user guide for structure of thesaurus configuration file

[hmaier-fws]

Create documentation that allows someone to create a valid thesaurus configuration file. As I understand the currently proposed process entails:

• A thesaurus manifest file (manifest.json), which identifies the thesauri and the uri to the associated thesauri configuration files.

• Each thesaurus configuration file provides a thesaurus citation (e.g., usgs citation) and a link to the associated keyword file or a keyword array (e.g., usgs keywords).

• Manifest file documentation

• Thesaurus configuration file documentation