Fixed parameters documentation by replacing underscores with hyphens

[LeonStoldt]

Hi, When using gcr cleaner with argument -tag_filter_any=.*, I received an error message like: flag provided but not defined: -tag_filter_any.

Usage of /bin/gcrcleaner:
Options:
  -dry-run
   [...]
  -tag-filter-all
  -tag-filter-any

I would guess the arguments have changed sometime and they haven't been updated in the Readme. So, I thought I'll create a PR to fix this :wink:

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[sethvargo]

Hi @LeonStoldt

That documentation is for calling gcr-cleaner-server via the API. In that case, underscores are correct. You can see the full list of flags and their accepted values for your version by running gcr-cleaner -h.

[LeonStoldt]

Hi @sethvargo, thanks for your quick response and information about when to use underscores. I did not know that and was confused while working with the gcr cleaner in a github action. Do you think it would be useful to add example flags like `-tag-filter-any' to the github actions example in order to prevent confusion when using it?