Add 3 open-source developer tools

[brancogao]

Added Tools

1. JSON Viewer (Browse JSON in TreeView section)

   • URL: https://json-viewer.autocompany.workers.dev/
   • Open-source JSON viewer with syntax highlighting and tree view

2. DNS Propagation Checker (DNS Checker section)

   • URL: https://dns-propagation-checker.autocompany.workers.dev/
   • Check DNS records across 10+ global DNS servers with propagation visualization

3. SSL Certificate Monitor (SSL/TLS Checker section)

   • URL: https://ssl-certificate-monitor.autocompany.workers.dev/
   • Monitor SSL/TLS certificate expiry and get alerts before they expire

All tools are:

• Free to use
• No login required
• Open-source (Cloudflare Workers)
• Works in browser

GitHub repos:

• https://github.com/brancogao/json-viewer
• https://github.com/brancogao/dns-propagation-checker
• https://github.com/brancogao/ssl-certificate-monitor