Update README.md

Author: pratit989

README.md

@@ -6,4 +6,4 @@ Get an API key from: <a href='cloudmersive.com/virus-api'>Cloudmersive Virus API
 # Instructions
 Step 1: Download the Source Code\
 Step 2: Install modules running the following command from the project folder ```pip install -r requirements.txt```\
-Step 3: Run ```GUI.exe```
+Step 3: Run ```GUI.py```