1.21.0

### 🆕 New Features
- #2489 Ability to clone monitors (Thanks @mathiash98 @chakflying)
- #1685 API Keys Management (Currently, it is used for Prometheus metrics API only) (Thansk @Computroniks)
- #2806 [Status Page] Add markdown support for description (Thanks @andreasbrett)
- #2531 [HTTP(s) Monitor] New Auth method: mTLS
- #2610 [HTTP(s) Monitor] Support XML Request Body (Thanks @bayramberkay @Genc @JustinTisdale)
- #2764 Add "Add New Tag" button in Settings (Thanks @chakflying)
- #939 Ability to set description of monitors (Thanks @jcvincenti)
- #2728 PagerTree Notification Provider (Thanks @armiiller)
- Update Apprise to 1.3.0
- #2191 Windows portable executable (uptime-kuma.exe) (Support Windows x64 only) (See `uptime-kuma-win64-portable-1.0.0.zip` below) 

### 🐛 Bug Fixes
- #2907 Redis monitor memory leak issue (Thanks @chakflying)
- #2776 Avoid generating maintenance timeslots endlessly for maintenance which causes high CPU usage and stuck at startup 
- #2835 The game list in the GameDig monitor returns nothing on first run (Thanks @chakflying)
- [Non-docker] Installation hangs on `npm run download-dist` on Node.js >= 18
- #2823 Status page will no longer throw error if description or footer is not set (Thanks @chakflying)
- #2876 [Push Monitor] Fix uptime cache issue (Thanks @chakflying)
- #2883 [Ping Monitor] Fix IPv6 issue
- #2880 Deleted monitor does not immediately disappear on a status page

### 💇‍♀️ Improvements
- #2786 Sort tags in the monitor list on dashboard (Thanks @luckman212)
- #2736 [Slack Notification] Better popup notification on mobile (Thanks @blozano824)
- #2748 Send status code `5XX` instead of `4XX` if it is database related errors (Thanks @chakflying)
- #2812 Better notification list
- #2334 #2595 #2716 [Telegram Notification] Support more options: protect forwarding, slient alert and message thread (topic) of the forum (Thanks @nlutsenko @tminei @Haythamasalama)
- #2744 Add ability to use User ID for LunaSea notifications (Thanks @bobby-ore)
- f47f2d5c8712bb41a1daf111629144b7dbf0aff3 Better save button for edit/add monitor page

### 🦎 Translation Contributors
- #2861 New language: Hebrew (he_IL) (Thanks @byawitz)
- #2789 New language: Urdu (Thanks @Zaid-maker)
- #2927 New language: Georgian (Thanks @Ghvinerias)
- #2788 #2890 #2913 Translations on Weblate. (Thanks @401U @Alanimdeo @AmadeusGraves @AnnAngela @DoyunShin @Genc @Ghvinerias @Gitricity @Jumala9163 @Kurty00 @MrEddX @Saibamen @TheSainEyereg @Tomasz365 @Zac10ck @Zaid-maker @Zandor300 @alex-connor @aosmirnov @bartcallant @black23 @byawitz @chakflying @ciccio0476 @cnlancehu @cyril59310 @deathart @dmitriev-ivan @furkanipek @fuyuki123 @ilya12077 @kiznick @marco-doerig @mathias56k @simonghpub @stanol @stianmeyer @theS1LV3R @tim-wiegers @victorpahuus ButterflyOfFire@Weblate Samuel-Perrier@Weblate krolli@Weblate)

### Others
- Other small changes, code refactoring and helps:
@OidaTiftla @spali @stanol @AlexKraus @tombii @401U
(Let me know if your name is missing. If your pull request have been merged in this version)