Update README.md

Author: RealAbdurRehman

README.md

@@ -2,10 +2,10 @@
 
 Your go to technical documentation page on CSS (Cascading Style Sheets).
 
-Bigger screen sizes view:
+### Bigger screen sizes view:
 <img src="https://github.com/RealAbdurRehman/css-documentation/blob/main/Preview1.png?raw=true" alt="Preview.">
 <img src="https://github.com/RealAbdurRehman/css-documentation/blob/main/Preview2.png?raw=true" alt="Preview.">
 
-Smaller screen sizes view:
+### Smaller screen sizes view:
 <img src="https://github.com/RealAbdurRehman/css-documentation/blob/main/Preview3.png?raw=true" alt="Preview.">
 <img src="https://github.com/RealAbdurRehman/css-documentation/blob/main/Preview4.png?raw=true" alt="Preview.">