Indent sections in the rule description guide to improve readability.
Cross-reference the link standard in the rule description guide.
## Review
A dedicated reviewer checked the rule description successfully for:
- [x] logical errors and incorrect information
- [x] information gaps and missing content
- [x] text style and tone
- [x] PR summary and labels follow [the
guidelines](https://github.com/SonarSource/rspec/#to-modify-an-existing-rule)
Created a tone guide to help rules authors make their content as
compelling for their users as possible.
## Review
A dedicated reviewer checked the rule description successfully for:
- [x] logical errors and incorrect information
- [x] information gaps and missing content
- [x] text style and tone
