Add Github Action for Publishing to Comfy Registry

[haohaocreates]

This PR adds a Github Action (publish-node-action) that will run whenever the pyproject.toml file changes. The pyproject.toml defines the custom node version you want to publish (added in another PR).

Action Required:

• Create an api key on the Registry for publishing from Github. Instructions.
• Add it to your Github Repository Secrets as REGISTRY_ACCESS_TOKEN.
  More info on the registry. Please message me on Discord if you have any questions!

[melMass]

Thanks Hao!
It should be good, I just need to move the action in the proper place (it's in issue templates for now) but I think we are good!
I'm going to try a first publish now