Doc cleanup

[brookslogan]

Checklist

Please:

• Make sure this PR is against "dev", not "main" (unless this is a release
  PR).
• Request a review from one of the current main reviewers:
  brookslogan, nmdefries.
• Makes sure to bump the version number in DESCRIPTION. Always increment
  the patch version number (the third number), unless you are making a
  release PR from dev to main, in which case increment the minor version
  number (the second number).
• Describe changes made in NEWS.md, making sure breaking changes
  (backwards-incompatible changes to the documented interface) are noted.
  Collect the changes under the next release number (e.g. if you are on
  1.7.2, then write your changes under the 1.8 heading).
• See DEVELOPMENT.md for more information on the development
  process.

Change explanations for reviewer

See #563 checklist. Some other items of note are deferred to https://github.com/cmu-delphi/forecasting-team-meta/issues/29.

Magic GitHub syntax to mark associated Issue(s) as resolved when this is merged into the default branch

• Resolves epiprocess doc cleanup #563

[brookslogan]

/preview-docs

[brookslogan]

Check issues are probably unrelated, from #631. Will work on that.

[github-actions]

🚀 Deployed on https://67d8adaa245c833df3631f1d--epiprocess.netlify.app

[brookslogan]

• Long epi_slide title makes it easy to skip (in html reference at least) and then the intro doesn't read that well.

[nmdefries]

Looks fine. I made a few small wording changes.

On the epix_slide reference page, do we need to show all these versions? Args look exactly the same.

[brookslogan]

I think roxygen adds those S3 method listings automatically. Any idea how to compress/remove them? I guess we could make them into function(...)'s that then forward to some internal epix_slide[grouped_]_epi_archive_impl functions, but I'm hoping there would be a straight roxygen solution.

[nmdefries]

Do the @keywords internal or @noRd work in this case?