When running in org_wide mode, the {repo} sentence makes less sense. Introduce a way to support that better

[bmuenzenmeyer]

https://github.com/target/create-meeting-issue/blob/main/src/lib/createIssueBody.ts#L9

This Action can be deployed a couple ways:

• each repo that wants to invoke it has a workflow, which means {repo} works okay
• a central repository of workflows has different versions of this action, allowing for central management and invocation on behalf of all.
  • this introduces problems, and perhaps i should disqualify it as a use case
    • not only would the {repo} need to change or be introduced as ENV, but the central repo would also need all the meeting.ics - maybe that's a feature though