Action's metadata

[tomaszmichalak]

Actions responds with transitions. Transitions are the Action's contract, they specify what the action can replay and how we can construct the graph. Currently Actions do not provide details about transitions.

Describe the solution you'd like
Every Action should define transitions it returns. Also some description could be added etc. So maybe we need some kind of action-name-metadata.yml file with its definition. This can be optional but it could help us with automatic graph validation.

Describe alternatives you've considered
Modify Action's API and add method returning allowed transitions.

Additional context

• automatic graph validation
• enable some graph design tools