ZSWatch / HeartRate-DevKit-HW - History

Prepare release

- Set variant to CHECKED
- Remove unused files
- Fix ERC errors
- Fix DRC errors
- Fix different documentation errors
- Fix different path errors for the release build
- Remove Power Sequencing page
- Add PDF_REPORT_ROOT_DIR variable to build
- Add script for CHANGELOG generation

Signed-off-by: Daniel Kampert <DanielKampert@kampis-elektroecke.de>