document compatibility alias

Follow Annotated Documents, including its optional installation and explicit-selection rules. Use kpop experimental annotated-doc. This alias preserves existing explicit invocations.

In ordinary conversation, name the product kpopper and describe the action in the user's language. Reserve the exact skill name kpopper:document for invocation instructions, technical documentation, debugging, or explaining this specific skill. Fold the product name into the explanation of the action; no extra announcement is needed.