Fix REST API link in info.xml

Updated REST API documentation link to version 3.

Signed-off-by: Christian Hartmann <chris-hartmann@gmx.de>

Author: Chartman123

appinfo/info.xml

@@ -13,7 +13,7 @@
 - **📝 Simple design:** No mass of options, only the essentials. Works well on mobile of course.
 - **📊 View & export results:** Results are visualized and can also be exported as CSV in the same format used by Google Forms.
 - **🔒 Data under your control!** Unlike in Google Forms, Typeform, Doodle and others, the survey info and responses are kept private on your instance.
-- **🧑‍💻 Connect to your software:** Easily integrate Forms into your service with our full-fledged [REST-API](https://github.com/nextcloud/forms/blob/main/docs/API.md).
+- **🧑‍💻 Connect to your software:** Easily integrate Forms into your service with our full-fledged [REST-API](https://github.com/nextcloud/forms/blob/main/docs/API_v3.md).
 - **🙋 Get involved!** We have lots of stuff planned like more question types, collaboration on forms, [and much more](https://github.com/nextcloud/forms/milestones)!
 	]]></description>