chore: update README.yaml to correct example usage of atmos-version#104

jasonwashburn wants to merge 2 commits intocloudposse:maincloudposse/github-action-setup-atmos:mainfrom

jasonwashburn:chore/fix-version-var-ref-in-readmejasonwashburn/github-action-setup-atmos:chore/fix-version-var-ref-in-readmeCopy head branch name to clipboard