docs: add reference video to ENV_SETUP guide with clear disclaimers

- Added YouTube reference video link at top of ENV_SETUP.md
- Included clear warnings that video is general reference only
- Emphasized following specific project steps over video
- Added visual reference notes in authentication section
- Added troubleshooting reference while maintaining project-specific guidance

Author: itskavin

ENV_SETUP.md

@@ -2,7 +2,15 @@
 
 This guide will walk you through setting up the required environment variables to download courses from Thinkific-based platforms.
 
-## 📋 Prerequisites
+## � **Reference Video (Optional)**
+
+For a general overview of using browser DevTools to extract authentication data, you can watch this reference video: **[How to Extract Authentication Data from Browser](https://youtu.be/owi-cOcpceI?t=60)**
+
+**⚠️ Important Note:** The video above is just a **general reference** for understanding browser DevTools concepts. **Follow the specific steps below for this Thinkific Downloader project**, as the exact fields and process may differ from the video.
+
+---
+
+## �📋 Prerequisites
 
 - A web browser (Chrome, Firefox, Edge, Safari)
 - Access to the course you want to download
@@ -44,6 +52,8 @@ Or manually create a `.env` file and copy the contents from `.env.example`.
 
 This is the most important step. You need to capture authentication cookies and timestamp.
 
+**📺 Visual Reference:** While the [video guide](https://youtu.be/owi-cOcpceI?t=60) shows similar concepts, **follow these exact steps below** for Thinkific-based platforms.
+
 #### **3.1 Open Developer Tools**
 
 **For Chrome/Edge:**
@@ -152,6 +162,8 @@ DEBUG=false
 
 ## 🚨 Troubleshooting
 
+**📺 Need visual help?** The [reference video](https://youtu.be/owi-cOcpceI?t=60) shows general DevTools concepts, but **follow our specific steps above** for this project.
+
 ### **Problem: Can't find course_player request**
 
 **Solutions:**