Prepare for GH marketplace

[grgur]

Here's the Marketplace publishing howto. One thing I noticed is that Dockerfile needs to be well commented.
Let's prepare Gimbal for Marketplace so we can publish when ready.

[mitchellsimoens]

We will need to copy in a couple files like the license and readme like they do in this Dockerfile.

[mitchellsimoens]

I also think we need to look at how we are going to publish the action. Right now, we are saying to use uses: ModusCreateOrg/gimbal/action@master which will always use latest and greatest which may not be stable. Now this will use latest deployed gimbal but there could be changes in the version in master that has pending changes needed for gimbal that hasn't been replaced.

Since we use tags for publishing, you can target a specific gimbal via uses: ModusCreateOrg/gimbal/action@v1.2.3 however there is a version mismatch in the action's Dockerfile since it uses FROM moduscreate/gimbal:latest, we'll need to replace that latest with a version when we publish and before the git tag is created.

[grgur]

I would hope that some of this would be automatic given that GitHub requires cutting a new release

[mitchellsimoens]

A new release is just a tag. Like instead of @master, you can use a tag like @1.2.3 that we have right now without anything else.