Update README.md

Author: RealAbdurRehman

README.md

@@ -1,3 +1,11 @@
 # css documentation
 
-Your go to technical documentation page on CSS (Cascading Style Sheets).
+Your go to technical documentation page on CSS (Cascading Style Sheets).
+
+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:
+<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.">