feat: Put tag name in output named 'tag'.

[jwalton]

This adds the tag name to the action's outputs, which lets you do things like:

      - uses: olegtarasov/get-tag@j1
        id: tagName
      - name: Push to ECR
        uses: jwalton/gh-ecr-push@master
        with:
          access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          local-image: my-image:release
          image: my-image:${{ steps.tagName.outputs.tag }}

You wouldn't be able to use the environment variable in the with section - need an output. :)

I wasn't sure how you went about building this, so you'll need to do that bit.

[olegtarasov]

Hi! Sorry for the late reply. I've merged your commit and will update the v1 tag shortly. Thank you!