Comply to requests made in the review and adjust to the Entry/Node changes

This commit:
* Turns `coverage_regex` into `coverage` entry in yml file
* Fixes smaller requests from code reviewers for the previous commit
* This commit is temporary (will be squashed afterwards)

This commit does not (further commits will do though):
* Add global `coverage` entry handling in yml file as suggested by Grzegorz
* Add specs
* Create changelog
* Create docs