Add quickstart info to the readme

[earth2marsh]

Better documentation for how to get api-linter up-and-running might reduce the hassle and work of figuring it out on your own. This probably belongs in a quickstart in the readme? Ideally we could provide a docker image with instructions for using it as a service as well. A GitHub action example might be helpful, too!

[earth2marsh]

Oh, some of these things are already mentioned in the /docs/ directory! This may be a combination of adding a link to: https://github.com/aep-dev/api-linter/blob/main/docs/index.md and possibly publishing a image to Docker Hub? (Plus a possible example GitHub action?)

[earth2marsh]

On today's call I said that I didn't think the linter could disable specific rules, but that's not true! Because it may take time for an existing org to become fully compliant with AEPs, being able to selectively lint could really help. To that end, perhaps the configuration docs could also be made more visible like install?