chore: point solid-ai-templates submodule at solid-ai-dev (#248)

The templates repository moved to the solid-ai-dev organisation. URL
change only; the pinned commit is unchanged.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: braboj

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "docs/solid-ai-templates"]
 	path = docs/solid-ai-templates
-	url = https://github.com/braboj/solid-ai-templates.git
+	url = https://github.com/solid-ai-dev/solid-ai-templates.git