Docs imply GitHub requires a core developer's approval for rule changes #952

The .github/CODEOWNERS comment and the doc-only rule sim.process.rule-machinery-code-owned say that changes to the rule files (rules/, scripts/rules/, scripts/run_quality_guards.py and CODEOWNERS) need a core developer's approval, and the CODEOWNERS comment says files outside that list "are not blocked". Read together, they say GitHub blocks a merge until a code owner approves.

GitHub doesn't. The default branch's ruleset (main, id 3680274) requires:

• a pull request with one approving review, from anyone with write access;
• passing CI complete and PR description checks.

Its require_code_owner_review is false. Listing a path in CODEOWNERS only makes GitHub request a review from @PolicyEngine/core-developers on pull requests that change it and aren't drafts.

The ruleset stays as it is. This issue covers correcting the docs:

• Reword the CODEOWNERS comment so it describes core-developer approval as a team convention and says what the ruleset enforces.
• Reword the statement of sim.process.rule-machinery-code-owned the same way, without changing what the rule asks for or its status, and regenerate docs/generated/rules.md and the AGENTS.md rules block.

#877 already corrected docs/engineering/skills/type-checking.md.