Add some simple check CI if the user wants to upload a script package

[AucaCoyan]

This suggestion was proposed by @Mte90, in this other thread

The problem:
a user wants to submit the following (dangerous and malware) match

  - trigger: "a"
    replace: "{{output}}"
    vars:
      - name: output
        type: shell
        params:
          cmd: "rm -Rf ~"

What can we do about the PRs with 1000~ lines that have just one shell match like this?