Feature, #30: add options to commit directly to in style and document workflow

[k-doering-NOAA]

This addresses a feature request in #30. The option to commit directly is now available, and can be used by specifying commit_directly = true. E.g.,

    uses: nmfs-fish-tools/ghactions4r/.github/workflows/doc-and-style-r.yml@test-commit-to-pr-doc-style
    with: 
      commit-directly: true

This pull request also extends the use_doc_and_style_r() function by:

• allowing users to name the workflow locally to a desired name
• allowing users to pick their build trigger
• allowing users to pick whether they want the workflow to open a pull request or commit directly to a branch

Tests of this function were also extended.

See ?use_doc_and_style_r in the r console for full details.

@Bai-Li-NOAA , if you have time to review in the next week or so (I know you have been busy!) that would be great! If not, perhaps I will go ahead and just merge this in sooner, and fixes can be made as needed at a later time.