chore: update README.md

Added action badges

README.md

@@ -1,5 +1,8 @@
 # Ypovoli
 
+![backend linting](https://github.com/SELab-2/UGent-7/actions/workflows/backend-linting.yaml/badge.svg)
+![backend tests](https://github.com/SELab-2/UGent-7/actions/workflows/backend-tests.yaml/badge.svg)
+
 This application was developed within the framework of the course "Software Engineering Lab 2" within the Computer Science program at Ghent University.
 
 ## Documentation