doc: Add some better examples for scripted diff
doc: Add some better examples for scripted diff

The current example isn't too great, for example it uses `find` instead
of `git ls-files`. Add a subsection with suggestions and examples.


Former-commit-id: 64f1ca6436a1677f98e45bae35fd8d8a77702007
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin