This PR addresses the audit efforts in #669 (closed). It:
- Adds a lede paragraph to standardize it, and shifts paragraph breaks around slightly for better flow
- References "people" in place of "users" where possible, to better align with our content styleguide
- Adds subheadings to section example code content
- Adds a reference to iOS dropping support for
user-scalable,min-scale, andmax-scale