Flatten contexts

This action can dump "flattened" GitHub contexts, which is more friendly than JSON for searching and debugging. 😀

Example usage

- name: Dump flattened GitHub contexts
  uses: vbem/flatten-contexts@v1

ID	Type	Default	Description
`sep`	String	`👉`	Separator between key and value

Name		Name	Last commit message	Last commit date
Latest commit History 22 Commits
.github		.github
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
action.yml		action.yml