chore: Add note about copyrights on PR checklist
- [ ] This board/shield is tested working on real hardware
- [ ] Definitions follow the general style of other shields/boards upstream ([Reference](https://zmk.dev/docs/development/new-shield))
- [ ] `.zmk.yml` metadata file added
- - [ ] Proper Copyright + License headers added to applicable files
+ - [ ] Proper Copyright + License headers added to applicable files (Generally, we stick to "The ZMK Contributors" for copyrights to help avoid churn when files get edited)
- [ ] General consistent formatting of DeviceTree files
- [ ] Keymaps do not use deprecated key defines (Check using the [upgrader tool](https://zmk.dev/docs/codes/keymap-upgrader))
- [ ] `&pro_micro` used in favor of `&pro_micro_d/a` if applicable
