Add redirect for old scene-editor/events help path (#691)

The help path /interface/scene-editor/events was referenced from
GDevelop core (e.g. SetHelpPath in conditions) but the page no longer
exists. Redirect it to the current events editor page at
/interface/events-editor/.

Co-authored-by: Claude <noreply@anthropic.com>

Author: 4ian

mkdocs.yml

@@ -124,6 +124,7 @@ plugins:
         "gdevelop5/publishing/android_and_ios/play-store/index.md": "gdevelop5/publishing/android/play-store/index.md"
         "gdevelop5/publishing/android_and_ios/play-store/upgrading-from-apk-to-aab.md": "gdevelop5/publishing/android/play-store/upgrading-from-apk-to-aab.md"
         "gdevelop5/interface/ask-ai.md": "gdevelop5/interface/ai/index.md"
+        "gdevelop5/interface/scene-editor/events.md": "gdevelop5/interface/events-editor/index.md"
         # Tutorials
         "gdevelop5/tutorials/platformer/start.md": "gdevelop5/tutorials/platformer/index.md"
         "gdevelop5/tutorials/asteroids/start.md": "gdevelop5/tutorials/asteroids/index.md"