Add StepActions to Catalog

[Yongxuanzhang]

Add StepActions to Catalog

[afrittoli]

@Yongxuanzhang thank you for this issue. I think it would be really good to have this implemented. Many of our tasks are single-step ones and having them as StepActions would improve their re-usability.
I was not involved in the discussion with ArtifactHub for Tasks and Pipelines, do you know what it would take to add a new type there? I think it would be great to start the conversation with the ArtifactHub team.
@chitrangpatel FYI

[Yongxuanzhang]

/assign

[Yongxuanzhang]

/kind feature

[Yongxuanzhang]

also related to tektoncd/pipeline#7329

[chitrangpatel]

For ArtifactHub, I believe it was this PR: https://github.com/artifacthub/hub/pull/2337/files# that added Tasks and Pipelines.

[chitrangpatel]

Rough Action plan:

• tektoncd/community#1137
• Then we probably will need support in tkn and catlin.
  • Is this a prerequisite or can it be done in parallel?
• We then add StepActions directory based structure to https://github.com/tektoncd/catalog
• Get back to the ArtifactHub Team to set up the StepAction catalog there.
• Update the CD job to also deploy stepactions to the bundle.
  • https://hub.tekton.dev/tekton/task/tekton-catalog-publish

[chitrangpatel]

cc @vinamra28