sqnc plugin uses ACTION

[frantjc]

i would like for the sqnc cli to have the following functionality:

sqnc plugin uses --git=/path/to/git ACTION [PATH]

should:

• clone the given action to the given path.
  • an example action might be charge/update-yaml-action/pr@v3. pseudo code for this example:
  • git clone --branch=@v3 https://github.com/charge/update-yaml-action > /dev/null
  • cat pr/action.yml || cat pr/action.yaml | convert_to_step
  • path should default to .
  • this command may assume that git is on the $PATH, but the path to the git binary should be an overridable flag
  • dont worry about assuming that the repo exists in the official github.com; will look into searching enterprise github domains sometime in the future

when converting an action to a step, ignore the existence of actions that have runs.using set to "composite", "Dockerfile" or runs.plugin to anything -- we will deal with those later if at all

additionally, ignore the case of an action using contexts e.g. ${{ github.sha }} -- we will deal with that later as well

if runs.using is "node12" or "node16", then the image should be node:12 or node:16 respectively :)