Fix screenshot filename case in README

Corrected image path from 'screenshot.png' to 'Screenshot.png' to match actual file name.
This fixes the broken image link in the README's Screenshot section.

Author: Syntax-Vibe-Amir

README.md

@@ -27,7 +27,8 @@ A lightweight Flask-based dashboard to monitor your system's real-time health 
 
 ## 📸 Screenshot
 
-![Dashboard Screenshot](screenshot.png)
+![Dashboard Screenshot](Screenshot.png)
+