E - JS docs: write page structure recipes and update linter to lint pages against recipes

[chinikes]

Epic

Acceptance Criteria

• [x] All pages in the JS doc set map to a recipe
• [x] We have an agreed specification describing the structures to lint for
• [ ] The linter implements checks for all the structures described in the specification
• [ ] The linter has internal tests of its own logic, as far as we have decided this is needed