Proposal 0017: yield metadata for unit-based scaling

[dubadub]

Summary

• Repurposes yield exclusively for measurable recipe output (e.g., yield: 500%ml) and removes it as a synonym for servings
• Resolves the ambiguity where yield meant both "serves N people" and the unit-based scaling output
• Keeps servings/serves for people count; supports single and multiple yield values so a recipe can be referenced by different units

Rendered proposal

Test plan

• Review proposal text for clarity and completeness
• Verify examples are correct and consistent with existing Cooklang syntax
• Confirm migration guidance (yield: 4 → servings: 4) is acceptable

[tmlmt]

The most natural use of servings, serves and yield to me (note: I am not an English native) are: “Serves 4,” “Yields 6 portions,” or “Makes 8 servings.". Given that, I kind of liked the simplicity of having to remember essentially two keys:

• servings / serves (same root): for number of people
• yield for the quantity produced (which corresponds to its dictionary definition)

Instead of having 6 different keys with half of them having ambiguous meaning.

[dubadub]

Agree, basically the way I had it in a doc then. I'll update the proposal