nextcloud: Install contacts and calendar apps

Currently, we have no good way to share calendars or track contacts within
Clicks. Luckily, NextCloud already supports both of these with Dav. These apps
add UI for the features in the NextCloud web app

Change-Id: I025246684321f8961587f552a9cab49b72e5ba31
diff --git a/modules/nextcloud.nix b/modules/nextcloud.nix
index d7d2490..a290a90 100644
--- a/modules/nextcloud.nix
+++ b/modules/nextcloud.nix
@@ -60,6 +60,16 @@
         "https://github.com/nextcloud-releases/richdocuments/releases/download/v8.2.0/richdocuments-v8.2.0.tar.gz";
       sha256 = "sha256-PKw7FXSWvden2+6XjnUDOvbTF71slgeTF/ktS/l2+Dk=";
     };
+    calendar = pkgs.fetchNextcloudApp {
+      url =
+        "https://github.com/nextcloud-releases/calendar/releases/download/v4.5.2/calendar-v4.5.2.tar.gz";
+      sha256 = "sha256-n7GjgAyw2SLoZTEfakmI3IllWUk6o1MF89Zt3WGhR6A=";
+    };
+    contacts = pkgs.fetchNextcloudApp {
+      url =
+        "https://github.com/nextcloud-releases/contacts/releases/download/v5.4.2/contacts-v5.4.2.tar.gz";
+      sha256 = "sha256-IkKHJ3MY/UPZqa4H86WGOEOypffMIHyJ9WvMqkq/4t8=";
+    };
   };
 
   sops.secrets.nextcloud_admin_password = {