[Book] consistent and complete config examples

Make configuration examples in the book consistent throughout the
different configuration formats. Also fixing several syntax issues.
minor #4114 [Book] consistent and complete config examples (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
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[Book] consistent and complete config examples

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets |

Make configuration examples in the book consistent throughout the different configuration formats. Also fixing several syntax issues.

Commits
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96fb64f [Book] consistent and complete config examples