Update CHANGELOG and Documentation

I've added all changes since 1.15 to the changelog, except all the BLE stuff. I'm not too sure what all the things were that have changed, so @schneider, if you can give me a rough list, I'll integrate them here as well.

changed milestone to %v1.16

Looks good to me! Thanks for keeping our codebase clean.

However, I'm only a bot - so a human will still have to approve this request.

• Fixed bug which triggered reboot loops
• Fixed bug which made the USB serial connection unresponsive

BLE:

• Added compatibility to BLE 5.0 capable phones (including iPhones).
• Improved BLE security by only allowing man-in-the-middle protected pairings and specifying minimum key lengths.
• Added pairing dialog in BLE app. Device is only visible when BLE app is active.
• Option to write HCI layer log files for debugging.
• Fixed bug which wrote the pairings file more periodically

added 8 commits

• d0b65c7e...64ea6680 - 5 commits from branch master
• 3ce8adc4 - Update CHANGELOG
• 0bd182b6 - docs(max86150): Document pycardium API
• 12b0d438 - docs(*): Add versionadded directives where applicable

Compare with previous version

added 3 commits

• 76c13383 - Update CHANGELOG
• dec0073e - docs(max86150): Document pycardium API
• c686b7cf - docs(*): Add versionadded directives where applicable

Compare with previous version

Added your changelog + anything we merged since I opened this MR.

merged

mentioned in commit 7422956c