Parameterise inputs

[amouat]

I'm wondering if we should give the user more control over the files that are searched.

At the moment the script does this:

        done < <(find "${{ inputs.working-dir }}" -type f \( -name "*.yaml" -o -name "*.yml" -o -name "Dockerfile*" -o -name "Makefile*" -o -name "*.sh" \) -print0)

In my case, this fails to pick up cross.Dockerfile. We could fix this by changing the regex to *Dockerfile* but maybe the user should be able to set specific files or regexs.