Update README.md

Author: jmayer913

README.md

@@ -58,6 +58,9 @@ On the flight schedule page, the user can delete a flight. The user will be requ
 
 <img width="399" alt="image" src="https://github.com/user-attachments/assets/cd04326b-4f16-4b9a-90e8-1f2a7a86b020" />
 
+## Edit Conflict
 
+When two users are editing an airline or flight at the same time, whoever submits first will win; the other user will be told to try again.
 
+<img width="400" height="188" alt="image" src="https://github.com/user-attachments/assets/f5c7e697-7ba7-4177-bd40-4be5d3a03a95" />