Add tip jar link to push notifications settings

Tusker/Screens/Preferences/Notifications/NotificationsPrefsView.swift

@@ -17,6 +17,15 @@ struct NotificationsPrefsView: View {
     
     var body: some View {
         List {
+            NavigationLink {
+                TipJarView()
+            } label: {
+                Text("Push notifications are available for free to all users, but providing them has an ongoing cost. If you like the app, please consider \(Text("supporting Tusker").foregroundColor(.accentColor)).")
+                    .font(.callout)
+                    .foregroundStyle(.secondary)
+            }
+            .listRowBackground(Color.accentColor.opacity(0.1))
+            
             Section {
                 ForEach(userAccounts.accounts) { account in
                     PushInstanceSettingsView(account: account)