Install TagBot as a GitHub Action

[JuliaTagBot]

You're receiving this pull request because the now-deprecated Julia TagBot GitHub App is installed for this repository. This pull request installs TagBot as a GitHub Action.
If this PR does not belong in this repository for any reason, feel free to close it.

See this Discourse thread for more details and to ask questions.
Please do not comment on this pull request, because it is unlikely that I (@christopher-dG) will see it.

[codecov-io]

Codecov Report

Merging #2 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master      #2   +/-   ##
======================================
  Coverage    83.9%   83.9%           
======================================
  Files           7       7           
  Lines         205     205           
======================================
  Hits          172     172           
  Misses         33      33

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[Wikunia]

If you consider merging this you might wanna add ssh: ${{ secrets.DOCUMENTER_KEY }} to it to create the docs automatically for a new stable release.
Currently the latest docs are from v0.3.3 instead of v0.4

[jkrumbiegel]

ah good point, where exactly should I add that? I think all my other repos got this automatically through PkgTemplates so I never touched the setup

[Wikunia]

It needs to be added as the last line with same indentation as token