Document allowlist for each module

Editor assessment

The subject completely describes the documentation task: the allowlist is documented for each module, with a meaningful api scope. The configuration surface, the per-module coverage, and the implied motivation (the allowlist's per-module flags were under-documented) are all evident, so no body is required. The docs type fits, no footers appear, and hygiene is clean, with imperative phrasing and no trailing period. The message tells developers exactly which configuration aspect gained systematic documentation, which fully satisfies the needs of a reference-docs addition.