Improve sidebar example copy-and-paste experience

[mcafaro]

GitHub shows a snippet of code to copy-and-paste when you search for this action in the marketplace sidebar while configuring a workflow.

Unfortunately the snippet of code they show will fail to work because the release input is empty.

I do not believe we can control what GitHub shows in this snippet, but perhaps we can modify how the release input is defined to improve this copy-and-paste experience. Or, at the very least, we can improve the error message that occurs when a user runs their YAML with release empty.