Update documentation Best Practices at minimum and target levels

[baagaard-usgs]

Minimum level - documentation is available online or offline.

Target level - documentation is in dynamic form (for example, html generated by Sphinx; Jupyter notebooks) and is available offline, which might be in a static form such as a PDF file.

Additional comments

• We do not want to constrain the form of the documentation or the way it is delivered.
• Ideally, the documentation should be available offline as it is desirable to be able to examine documentation without an internet connection.
• There are lots of ways to generate documentation that are more dynamic or interactive. The most common way to do this is through Sphinx, which can generated both html and PDF files; the html version is more dynamic. Jupyter notebooks are another way to generate dynamic, interactive documentation.