feat: create output for version

[jef]

Description

It would be really handy if the action created a few outputs that would be useful for later steps like:

• tag: 1.0.0
• commit: 62a67966c87f04fba1944c0fe548b018864bad71

[bcoe]

@jef this seems like it would be a pretty reasonable addition. I think we'd need to make release-please return an object with this information when run programmatically perhaps?

[jef]

That's a good question. If release-please uses @actions/core, this could make this pretty straight forward (hopefully)!

https://github.com/actions/toolkit/tree/master/packages/core#inputsoutputs

[jef]

Or how ever this action interacts with release-please to be able to return that information. Then run core.setOutput on that value since release-please is outside of this action's scope.