Update challenge_19.md

Signed-off-by: sreejasaha19 <105979237+sreejasaha19@users.noreply.github.com>

Author: shivaylamba

Challenges/challenge_19.md

@@ -10,3 +10,4 @@ So in order to ensure proper codestyling and structure, there are checks run on
 Task: 
 1. Create a new file inside your branch created in previous challenges ``your-username-details`` under the directory ``contributors/username``. The file needs to be a source code file written in your preferred programming language. The code can be anything you want: hello world program or your favorite program. 
 2. Commit the change and push it. 
+3. Check if your linting fails in side the Pull request: <img width="870" alt="image" src="https://user-images.githubusercontent.com/19529592/190969615-f3205b26-83eb-4b5f-b7a5-19567a575a9a.png"> then lint your code to ensure that this check passes inside your pull request.