Species comments

[IJBG]

Ready for review! Changes:

• [x] added R/prepare_stop_level_data - processes species_comments column to stop-level data. In comments have outline of building out the function to take ALL the stop-level data and handle it together.
• [x] minor updates to R/process_observers (mostly fixing comments for clarity)
• [x] Re-compressed everything in data/ - this fixed a CRAN check warning, file content appears unaffected. ! Before merging this pull request though I will run an anti-join just to confirm.
• [x] Renamed some stop-level excel files to pass CRAN checks

In the spirit of small branches and pull requests, I'll open a new branch for the next step in processing stop-level data. This pull request finishes out work with the new species_comments column to get information from within the notes for a species within an ebird checklist.

[IJBG]

Yep, no problems with the anti-join for durham and orange, so no like, error'd changes to data with the updated compression. mbbs_chatham is different but I also downloaded a new mbbs_chatham to fix some other errors so that's expected.

[bsaul]

@IJBG - I'll open a new issue regarding my comments ☝🏼 and then go ahead and merge.