Command Schema

While the Wasm calls (instantiate, execute, query) accept JSON, this is not enough information to use it. We need to expose the schema for the expected messages to the clients. You can generate this schema by calling cargo schema, which will output 4 files in ./schema, corresponding to the 3 message types the contract accepts, as well as the internal State.

These files are in standard json-schema format, which should be usable by various client side tools, either to auto-generate codecs, or just to validate incoming json wrt. the defined schema.