Update README with advent calendar (#36172)

* update readme

* fix spellcheck

.github/actions/spell-check/allow/names.txt

@@ -44,6 +44,7 @@ Bartosz
 betadele
 betsegaw
 bricelam
+bsky
 CCcat
 Chinh
 chrdavis
@@ -90,6 +91,7 @@ Kairu
 Kamra
 Kantarci
 Karthick
+kaylacinnamon
 kevinguo
 Krigun
 Lambson

.github/actions/spell-check/expect.txt

@@ -667,6 +667,7 @@ Iindex
 IJson
 Ijwhost
 IKs
+iljxck
 ILogon
 IMAGEHLP
 IMAGERESIZERCONTEXTMENU
@@ -770,6 +771,7 @@ lastcodeanalysissucceeded
 Lastdevice
 LASTEXITCODE
 LAYOUTRTL
+lcb
 LCIDTo
 lcl
 Lclean

README.md

@@ -1,6 +1,6 @@
 # Microsoft PowerToys
 
-![Hero image for Microsoft PowerToys](doc/images/overview/PT_hero_image.png)
+![Hero image for Microsoft PowerToys](doc/images/overview/PT_holiday_hero_image.png)
 
 [How to use PowerToys][usingPowerToys-docs-link] | [Downloads & Release notes][github-release-link] | [Contributing to PowerToys](#contributing) | [What's Happening](#whats-happening) | [Roadmap](#powertoys-roadmap)
 
@@ -20,6 +20,12 @@ Microsoft PowerToys is a set of utilities for power users to tune and streamline
 | [Registry Preview](https://aka.ms/PowerToysOverview_RegistryPreview) | [Screen Ruler](https://aka.ms/PowerToysOverview_ScreenRuler) | [Shortcut Guide](https://aka.ms/PowerToysOverview_ShortcutGuide) |
 | [Text Extractor](https://aka.ms/PowerToysOverview_TextExtractor) | [Video Conference Mute](https://aka.ms/PowerToysOverview_VideoConference) | [Workspaces](https://aka.ms/PowerToysOverview_Workspaces) |
 
+## 🎁⭐ PowerToys Advent calendar ⭐🎁
+
+We will be highlighting a cool utility each day for 24 days in December! To follow along, check out these threads:
+- https://bsky.app/profile/kaylacinnamon.bsky.social/post/3lcb7iljxck2o
+- https://x.com/cinnamon_msft/status/1863284610773246257
+
 ## Installing and running Microsoft PowerToys
 
 ### Requirements