adjust README.md with frontend repo link provided

media-store/README.md

@@ -6,7 +6,7 @@ It contains these folders and files, following our recommended project layout:
 
 File or Folder | Purpose
 ---------|----------
-`app/` | content for UI frontends goes here
+`app/` | Contains already bundled js code from [this repository](https://github.com/Dmitriynj/media-store-front)
 `db/` | your domain models and data go here
 `srv/` | your service models and code go here
 `package.json` | project metadata and configuration
@@ -18,6 +18,7 @@ File or Folder | Purpose
 - Open a new terminal and run `cds watch` 
 - (in VS Code simply choose _**Terminal** > Run Task > cds watch_)
 - Start adding content, for example, a [db/schema.cds](db/schema.cds).
+- To adjust UI simply clone [this](https://github.com/Dmitriynj/media-store-front) repo. Run `yarn start` for development. When you are done, run `yarn build` and copy all files from '/build' to the '/app' folder of the current repo.   
 
 
 ## Learn More

media-store/srv/browse-tracks-service.cds

@@ -10,7 +10,7 @@ service BrowseTracks {
     entity Tracks as projection on my.Tracks;
 
     @(requires : ['authenticated-user'])
-    action getInvoicedTracks() returns array of {
+    function getInvoicedTracks() returns array of {
         ID         : Tracks.ID;
         trackName  : Tracks.name;
         genreName  : my.Genres.name;