Update Reddit link, fix end date on webinar (#103)

* Switch to official Reddit link

* Set correct end-date for Splat webinar

* Auto-update submodules

* Auto-update submodules

---------

Co-authored-by: James Riordon <jriordon@outofcontrol.ca>
Co-authored-by: Read the Docs Bot <rtd-bot@shader-slang.com>

Author: 3 people

_data/social.json

@@ -21,7 +21,7 @@
   },
   {
     "name": "Reddit",
-    "link": "https://www.reddit.com/r/SlangShadingLanguage",
+    "link": "https://www.reddit.com/r/shaderslang/",
     "image": "images/social/reddit-dark.svg"
   }
 ]

_posts/2025-05-10-getting-started-with-slang.md

@@ -2,7 +2,7 @@
 layout: event
 title: "Getting Started with Slang: Draw Your First Splat"
 date: 2025-04-30 17:00:00
-end_date: 2025-05-10 17:00:00
+end_date: 2025-05-21 17:00:00
 categories: [ "event" ]
 tags: [slang]
 author: "Shannon Woods, NVIDIA, Slang Working Group Chair"