docs(readme): explain purpose of this repo and interplay with other repos

README.md

 # Ahiqar Frontend
 
-The (static) frontend for the Ahiqar project. <https://ahikar.sub.uni.goettingen.de>
+The (static) frontend for the Ahiqar project: <https://ahikar.sub.uni.goettingen.de>
+
+This repository mainly serves as a project specific customization of the EMo QViewer.
+
+It is integrated into the QViewer during the build of the backend, cf. <https://gitlab.gwdg.de/subugoe/ahiqar/backend#get-the-frontend>.