add slides for my Moodle TinyMCE Premium features

Author: fharper

src/data/talks.json

@@ -15,7 +15,8 @@
         "country": "gb",
         "city": "Edinburgh, Scotland",
         "date": "2025-09-16",
-        "type": "talk"
+        "type": "talk",
+        "slide": "https://fred.dev/slides/2025-09-16_-_MoodleMoot_-_Supercharge_Moodle_Course_Design_with_TinyMCE_Premium_Tools.pdf"
     },
     {
         "title": "Common bottlenecks in collaborating on written content at scale",