Remove duplicate documentation. (#373)

* Remove duplicate documentation.

* Add test configuration header back in main README.

* Add missing regex operator in docs/README.

* Fix incorrect description of configuration options bins, confs etc.

* Move description of version auto-detection to main README.

* Use 1.13 in examples since cfg/1.12 doesn't exist

* Remove duplicate sentence about regex

This sentence is now in the docs/README

* Add link to the docs for test YAML definitions