Validate by default

[abelsiqueira]

Instead of no args. Just adding the following in action.yml should be enough:

  args:
    - "--validate"

[jspaaks]

When I tried to update action.yml previously, all jobs became validation jobs somehow. I couldnt figure out what went wrong, so I settled for having the action print the --help when the user doesnt specify any args.

[abelsiqueira]

I had the same issue as @jspaaks and other possible solutions are not trivial.