fix: Fact-check of configuration, caching, logging, and modules

[Swiftaxe]

Summary

Fact-checked, removed noise, and added frontmatter to 4 pages.

All 4 files:

• Added missing description frontmatter

07-configuration:

• Title "Configurations" → "Configuration" (singular concept page)
• Removed redundant **Example:** label

08-caching:

• Fixed missing await on UserData.db.findById call (bug — assigns a Future not the resolved value)
• Removed "In total," filler
• Removed "simply" filler

09-logging:

• Fixed typo "Defaults values" → "Default values"

10-modules:

• No content changes beyond frontmatter