Cleanup unnecessary comments/improve docs.
Cleanup unnecessary comments/improve docs.

This is part of a refactor of extractnumber_en, with the ultimate
goal of making it easier to maintain and extend (should also
improve perf).  This is in support of issues-1959.

forslund/mycroft-core,MycroftAI/mycroft-core,forslund/mycroft-core,Dark5ide/mycroft-core,Dark5ide/mycroft-core,MycroftAI/mycroft-core