Revise Hugging Face Upload Guide

[egrace479]

Address git lfs vs hugging face CLI or API.

[egrace479]

Notes on updated .gitignore guidance (in #46) should also be considered. Summarized below for ease of reference:

.gitignore may not be as relevant if not interacting with HF through git or git lfs. However, ignoring particular files is still a topic that should be addressed (as we did with a note for CITATION.cff and clarifying the licensing descriptions in #51).
@hlapp: Off the top of my head I'm not sure whether there isn't also a file the HF CLI honors for determining what to ignore, though scrolling through the documentation suggests that --exclude is the only mechanism.