Style update

[thomas-robinson]

Description
This is a code style update to reflect using the fms_ prefix for modules and routines that are public.

Fixes # (issue)

How Has This Been Tested?
Documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included
• make distcheck passes

[bensonr]

The use of public here and in the sample code below isn't what's captured in lines 13-15 above where it simply says fms_subfolder_. The inclusion of public implies we want everything to have public included in the naming scheme. I'd also recommend not have the double example called out here.