Merge pull request nus-cs2103-AY2324S1#34 from jianrong7/add-nfr

add all nfr

docs/DeveloperGuide.md

@@ -348,10 +348,18 @@ Priorities: High (must have) - `* * *`, Medium (nice to have) - `* *`, Low (unli
 ### Non-Functional Requirements
 
 1.  Should work on any _mainstream OS_ as long as it has Java `11` or above installed.
-2.  Should be able to hold up to 1000 persons without a noticeable sluggishness in performance for typical usage.
+2.  Should be able to hold up to 1000 properties and clients without a noticeable sluggishness in performance for typical usage.
 3.  A user with above average typing speed for regular English text (i.e. not code, not system admin commands) should be able to accomplish most of the tasks faster using commands than using the mouse.
-
-*{More to be added}*
+4.  The system should respond within two seconds.
+5.  The product is offered as a free application.
+6.  The user interface should be intuitive enough for property agents who are not IT-savvy.
+7.  Should work on any computer fewer than five years old.
+8.  Should work without requiring an installer.
+9.  Should not require access to an internet connection.
+10. Should save data locally in a human editable file.
+11. Should have a graphical user interface with readable font of at least size 11.
+12. Should have a graphical user interface which is intuitive and user-friendly.
+13. Should not require user to have any prior technical knowledge or expertise.
 
 ### Glossary