[ruff-0.8] Spruce up docs for newly stabilised rules (#14466)
## Summary
- Expand some docs where they're unclear about the motivation, or assume
some knowledge that hasn't been introduced yet
- Add more links to external docs
- Rename PYI063 from `PrePep570PositionalArgument` to
`Pep484StylePositionalOnlyParameter`
- Rename the file `parenthesize_logical_operators.rs` to
`parenthesize_chained_operators.rs`, since the rule is called
`ParenthesizeChainedOperators`, not `ParenthesizeLogicalOperators`
## Test Plan
`cargo test`
