ci: add an action to automatically close stale issues and PRs

Add sync_issues GitHub Action for workflows

Merge pull request #3 from bmcdonnell/alarm-bugfix

fix typos

Retrieve the correct alarm time

Updated library.properties to include in Arduino Library Manager

Merge pull request #2 from ciniml/use_crystal

Use XOSC32K for RTC if extrenal 32.768k oscillator is available on the platform.

The standard time zone does not need to be minus 8.

fixed some issues.

Fixed the issue of clock inaccuracy after power on again

Update issue templates

Create CONTRIBUTING.md

Create CODE_OF_CONDUCT.md

update travis.