Fix the path in the python template (#12460)

Also use a link

Author: eerhardt

src/Aspire.ProjectTemplates/templates/aspire-py-starter/13.0/app/app.py

@@ -60,10 +60,10 @@ def get_redis_client():
 
 
 if not os.path.exists("static"):
-    @app.get("/")
+    @app.get("/", response_class=fastapi.responses.HTMLResponse)
     async def root():
         """Root endpoint."""
-        return "API service is running. Navigate to /weatherforecast to see sample data."
+        return "API service is running. Navigate to <a href='/api/weatherforecast'>/api/weatherforecast</a> to see sample data."
 
 @app.get("/api/weatherforecast")
 //#if UseRedisCache