Update assignment3.md

assignments/assignment3.md

-
 # Assignment 3
 
 Hey there! Welcome to Knowledge Lens Intern Training Program.
@@ -148,7 +147,7 @@ data can be of different quality - Good ( 0 ), Maintainance ( 1 ), Error ( 2 )
 
 Based on the quality of data update to different Redis database.
 
-sample data format: 
+Sample data format: 
 ```json
   {
 		"data" : { "PM10" : 100 , "PM2.5": 23, "SO2":21, "NO2": 32}