If a file is modified, copyright year can be updated automatically.
For example, a modified file with Copyright 2020 by XXX, can be updated to:
Copyright 2020-2021 by XXX.
If multi copyrights exist in one file, it is possible to update a certain copyright.
Outstanding work:
[x] don't add a blank line after copyright statement, if there wasn't one before
[x] allow configuration of --primary-entity in config files
Tool to maintain/update copyright notices:
Outstanding work:
--primary-entityin config files