Update README.md

Author: rich-iannone

README.md

@@ -221,6 +221,14 @@ Click the following headings to see some video demonstrations of the CLI:
 <img src="https://posit-dev.github.io/pointblank/assets/vhs/cli-essential-validations.gif" width="100%">
 </div>
 
+</details>
+<details>
+<summary>Using Polars in the CLI</summary>
+
+<div align="center">
+<img src="https://posit-dev.github.io/pointblank/assets/vhs/cli-using-polars.gif" width="100%">
+</div>
+
 </details>
 <details>
 <summary>Integrating Pointblank with CI/CD</summary>