Add documentation for Arazzo rules and linting

[DmitryAnansky]

Describe the bug

New rules for AsyncAPI and Arazzo are not described in config sections like
https://redocly.com/docs/cli/rules/recommended.

We need to update it for all config pages: all, recommended, minimal, strict-recommended.

Also, lest review severity levels in predefined rulesets. Check with @tatomyr and @lornajane

[lornajane]

Also to include with these docs changes:

• a new top-level configuration entry arazzoRules
• we'll need additional ruleset documentation for each rule that was added, and for the arazzo version of the minimal/recommended/etc rulesets

[JLekawa]

Blocked until #1800 merges.