docs: Enable all features in docs.rs and add multitest docs comments

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 85.25%. Comparing base (b7052b5) to head (d841343).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #332 +/- ## ======================================= Coverage 85.25% 85.25% ======================================= Files 37 37 Lines 2700 2700 ======================================= Hits 2302 2302 Misses 398 398 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[jawoznia]

211