Allow for specific includes and excludes

[bewuethr]

Add action parameters that allow to include and exclude specific files to be checked/ignored.

[asbjornu]

Could this include the --external-sources argument? It would be great to have a with property in which all possible arguments supported by shellcheck could be configured:

- name: Shellcheck
  uses: bewuethr/shellcheck-action@v2
  with:
    external_sources: .env
    severity: info
    include: [CODE1, CODE2]
    exclude: [CODE4, CODE5]

[bewuethr]

@asbjornu Definitely a good suggestion 🙂 I've spun it out into its own issue. This issue here is meant to include/exclude specific files, which is more of a function of how the action finds the files to check (with a somewhat convoluted find command, that is).

[asbjornu]

I see. Since shellcheck has its own include/exclude arguments, I assumed that was it. I'll subscribe to #4 and follow up there, then. Thanks!