Add missing examples

Author: Ndpnt

.env.example

@@ -1,8 +1,21 @@
-OTA_ENGINE_SENDINBLUE_API_KEY='xkeysib-3f51c…'
-OTA_ENGINE_SMTP_PASSWORD='password'
+# Open Terms Archive Engine - Environment Variables Example
+# Copy this file to .env and fill in your actual values
 
-# If both GitHub and GitLab tokens are defined, GitHub takes precedence for dataset publishing
-OTA_ENGINE_GITHUB_TOKEN=ghp_XXXXXXXXX
+OTA_ENGINE_GITHUB_TOKEN=your_github_token_here
+OTA_ENGINE_GITLAB_TOKEN=your_gitlab_token_here
+OTA_ENGINE_GITLAB_RELEASES_TOKEN=your_gitlab_releases_token_here
+OTA_ENGINE_SENDINBLUE_API_KEY=your_sendinblue_api_key_here
+OTA_ENGINE_SMTP_PASSWORD=your_smtp_password_here
 
-OTA_ENGINE_GITLAB_TOKEN=XXXXXXXXXX
-OTA_ENGINE_GITLAB_RELEASES_TOKEN=XXXXXXXXXX
+HTTP_PROXY=http://proxy.example.com:8080
+HTTPS_PROXY=https://proxy.example.com:8080
+
+# Alternative lowercase versions (some systems prefer these)
+http_proxy=http://proxy.example.com:8080
+https_proxy=https://proxy.example.com:8080
+
+# Disable headless mode for Puppeteer (shows browser window)
+FETCHER_NO_HEADLESS=1
+
+# Disable Chrome sandbox (required for some Docker environments)
+FETCHER_NO_SANDBOX=1