Merge pull request #3286 from nhutlong-nguyen/patch-1

Update part1d.md

Author: mluukkai

src/content/1/en/part1d.md

@@ -1236,7 +1236,7 @@ Change your application to display statistics only once feedback has been gather
 
 Let's continue refactoring the application. Extract the following two components:
 
-- <i>Button</i> Handles the functionality of each feedback submission button.
+- <i>Button</i> handles the functionality of each feedback submission button.
 
 - <i>StatisticLine</i> for displaying a single statistic, e.g. the average score.