Describe what the patron id is for translations

- Resolves: #413

gui/qml/LoginDialog.qml

@@ -17,6 +17,7 @@ Dialog {
         }
         TextField {
             id: username
+            //: Ask for the library card number
             placeholderText: qsTr("Patron ID")
         }
         TextField {
@@ -32,6 +33,7 @@ Dialog {
 
     function getLoginText() {
         if (allowEmptyPass) {
+            //: Ask for the library card number
             return qsTr("Enter your Patron ID")
         } else {
             return qsTr("Log in with your library credentials")

gui/qml/main.qml

@@ -59,6 +59,7 @@ ApplicationWindow {
               if (allowEmptyPass) {
                   // For now, this is a libraryVPN, so we can be explicit about what credentials are here.
                   // Another option to consider is to customize the error strings while vendoring.
+                  //: Incorrect library card number
                   msg = qsTr("Please check your Patron ID")
               } else {
                   msg = qsTr("Could not log in with those credentials, please retry")