github doc for manual workflow dispatch is missing

[eilidhmae]

Clicking the link in this document results in a 404.

[eilidhmae]

https://github.com/peter-evans/slash-command-dispatch/blame/5104d929e1f1589fee4a8b5037304f9fa823315e/docs/workflow-dispatch.md#L5C3-L5C3

[peter-evans]

Fixed it now. Thank you.