feat: add terminal demo GIF to README

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: badchars

.github/demo.gif

@@ -0,0 +1,30 @@
+# VHS Demo — osint-mcp-server
+Output .github/demo.gif
+
+Set Shell "bash"
+Set FontSize 14
+Set Width 900
+Set Height 550
+Set Theme "Catppuccin Mocha"
+Set Padding 20
+Set TypingSpeed 35ms
+
+# List all tools
+Type `npx osint-mcp-server --list`
+Sleep 300ms
+Enter
+Sleep 5s
+
+# DNS lookup
+Type `npx osint-mcp-server --tool dns_lookup '{"domain":"example.com","type":"A"}'`
+Sleep 300ms
+Enter
+Sleep 5s
+
+# Email security check
+Type `npx osint-mcp-server --tool dns_email_security '{"domain":"example.com"}' --format text`
+Sleep 300ms
+Enter
+Sleep 8s
+
+Sleep 3s

.github/demo.tape

@@ -62,6 +62,10 @@
   <img src="https://img.shields.io/badge/free%20tools-21-22c55e" alt="21 Free Tools">
 </p>
 
+<p align="center">
+  <img src="https://raw.githubusercontent.com/badchars/osint-mcp-server/main/.github/demo.gif" alt="osint-mcp-server demo" width="800">
+</p>
+
 ---
 
 ## The Problem