Add Element X iOS entries in the apple-app-site-association. (#337)

* Add Element X to the apple-app-site-association file.

* Tidy up the generated apple-app-site-association file.

scripts/build.js

@@ -124,10 +124,9 @@ async function buildJs(mainFile, assets, extraFiles = []) {
 }
 
 function buildAppleAssociatedAppsFile(clients) {
-    const appIds = clients.map(c => c.appleAssociatedAppId).filter(id => !!id);
+    const appIds = clients.map(c => c.appleAssociatedAppId).flat().filter(id => !!id);
     return JSON.stringify({
         "applinks": {
-            "apps": [],
             "details": {
                 appIDs: appIds,
                 components: [
@@ -136,9 +135,6 @@ function buildAppleAssociatedAppsFile(clients) {
                     }
                 ]
             },
-        },
-        "webcredentials": {
-            "apps": appIds
         }
     });
 }