basic: Added sub command
basic: Added sub command

* Added sub command which encapsulates 'sed substitution' in a command.

* Moved the regular expression which matches the sed substitution
  syntax into a separate variable.

* Did some janitoring throughout the file.

Signed-off-by: mr.Shu <8e7be411ad89ade93d144531f3925d0bb4011004@shu.io>

mrshu/brutal-plugins