docs: remove reference files in source

[lukegalbraithrussell]

Summary

Checking in the autogenerated reference files to github is just a lot. They autogenerate on build so they don't need to be in source. This removes them from the repo and makes sure they stay removed

Failing tests will pass once #1895 is merged

Requirements (place an x in each [ ])

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.85%. Comparing base (deb51ea) to head (7959f01).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1896   +/-   ##
=======================================
  Coverage   89.85%   89.85%           
=======================================
  Files          34       34           
  Lines        7648     7648           
  Branches      374      374           
=======================================
  Hits         6872     6872           
  Misses        764      764           
  Partials       12       12           

Flag	Coverage Δ
cli-hooks	94.94% <ø> (ø)
cli-test	94.77% <ø> (ø)
oauth	76.53% <ø> (ø)
socket-mode	59.59% <ø> (ø)
web-api	96.57% <ø> (ø)
webhook	95.27% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[filmaj]

The changes look good to me but I did notice the documentation GitHub Action had some warnings and errors: https://github.com/slackapi/node-slack-sdk/actions/runs/10470951573/job/28997183768?pr=1896

Should we look into those while we're here? I can assist with this as well

[lukegalbraithrussell]

The error has been appearing on previous ones too -- https://github.com/slackapi/node-slack-sdk/actions/runs/10325270022/job/28586508803. I'm going to merge this since its status quo and then look into it