Add link to back-end repo

Author: choerubi

README.md

@@ -2,7 +2,7 @@
 
 [![CI](https://github.com/Usin2705/CaptainA_unity/actions/workflows/ci.yml/badge.svg)](https://github.com/Usin2705/CaptainA_unity/actions/workflows/ci.yml)
 
-Welcome to the repository of SaySuomi (previous name CaptainA), a mobile application designed to help users practice their Finnish pronunciation. This repository contains the code for both the mobile application and the backend server.
+Welcome to the repository of SaySuomi (previous name CaptainA), a mobile application designed to help users practice their Finnish pronunciation. This repository contains the code for the mobile application. The server-side code can be found [here](https://github.com/aalto-speech/dta-server/tree/dev).
 
 ## Front end development project description: