1.15.0

• ⚠️ Change the priority of arguments (Arguments > Environment Variables) (Thanks @marcules)
  (It might be a breaking change for someone who set both arg and env var with different values. I guess it should be not common.)
• Add new monitor type: MQTT (Thanks @tarun7singh and @chakflying)
• Fix restore backup file issue.
• [Status Page] Custom CSS (Thanks @patrickhafner)
• [Status Page] Footer Text
• [Status Page] Show/Hide Powered by Uptime Kuma
• Add dropdown menu and easier to find logout button (Thanks @Computroniks and @chakflying)
• Better logging format (Thanks @andreasbrett)
• Add notification: OneBot (Thanks @ColdThunder11)
• Add notification: PushDeer (Thanks @ngc7331)
• Update Apprise to 0.9.8
• Update SQLite from 3.36 to 3.38

How to update? Please read this:
https://github.com/louislam/uptime-kuma/wiki/%F0%9F%86%99-How-to-Update

Bug report:
https://github.com/louislam/uptime-kuma/issues

Thank you all contributors! Bug fix, code refactoring, language files update and code review!
@fluencydoc @Alexandre-Gliganic @c0derMo @AnnAngela @MrEddX @sovushik @DX37 @PhyxionNL @koen20 @SiderealArt @mathiskir @gaby