Document special prefixes emitted by manifest releases

[bcoe]

We should document the outputs set by manifest releases, e.g., path--tag_name, releases_created.

[hugomrdias]

"releases_created": "true",
"packages/one--release_created": "true",
"packages/one--major": "1",
"packages/one--minor": "2",
"packages/one--patch": "2",
"packages/one--sha": "fe5efccaf5c3d11c18f5a357e848276ec6cc1180",
"packages/one--version": "1.2.2",
"packages/one--pr": "27",
"packages/one--html_url": "https://github.com/hugomrdias/mono-release/releases/tag/one-v1.2.2",
"packages/one--name": "one one-v1.2.2",
"packages/one--tag_name": "one-v1.2.2",
"packages/one--upload_url": "https://uploads.github.com/repos/hugomrdias/mono-release/releases/48621032/assets{?name,label}",
"packages/one--draft": "false",
"packages/one--body": "\n\n### Bug Fixes\n\n* **one:** ddd ([56625f7](https://www.github.com/hugomrdias/mono-release/commit/56625f7922d6dd3a95eb703629565eeeacdcdec2))\n"

Theres an issue if you use a folder for your packages, github doesnt like slashs in the outputs vars and raises a Unexpected symbol error

[hugomrdias]

found a solution if: ${{ steps.tag-release.outputs['packages/two--release_created'] }}

[ChipWolf]

I don't see any of these special outputs from the manifest releaser @bcoe @hugomrdias, did either of you do something special for this behavior?

[bcoe]

Some of these outputs may be related to the regression @phated mentions, will look soon.

[tasshi-me]

Thank you for the @hugomrdias's solution https://github.com/google-github-actions/release-please-action/issues/297#issuecomment-907698520. It worked for my problem.

However, I think it is better to replace special symbols like / with - or _.

https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#outputsoutput_id

The <output_id> must be a unique identifier within the outputs object. The <output_id> must start with a letter or _ and contain only alphanumeric characters, -, or _.