docs: remove mention of priority

src/main/java/appointmentplanner/api/Appointment.java

@@ -28,8 +28,8 @@ public interface Appointment extends TimeSlot {
     AppointmentRequest request();
 
     /**
-     * Override the default toString. toString() returns startTime, endTime,
-     * description and priority like: "2020-09-12 14:00 - 15:55 ALDA Lesson"
+     * Override the default toString. toString() returns startTime, endTime and description
+     * like: "2020-09-12 14:00 - 15:55 ALDA Lesson"
      * This will make your testing and debugging life so much easier.
      *
      * @return String representation of Appointment.

src/main/java/appointmentplanner/api/AppointmentData.java

@@ -9,7 +9,7 @@
  * taking 45 minutes.
  *
  * Another example is having a treatment at a dentist or a beauty parlor. The
- * duration, priority, and description are known, but there is no time or date
+ * duration and description are known, but there is no time or date
  * allocated yet.
  *
  * @author Pieter van den Hombergh {@code [email protected]}
@@ -31,8 +31,7 @@ public interface AppointmentData {
     String description();
 
     /**
-     * Get the textual representation of AppointmentData. Contains description,
-     * duration and priority.
+     * Get the textual representation of AppointmentData. Contains description and duration.
      *
      * @return AppointmentData text.
      */