Examine source code of Yahoo Wider Mail

{
  "manifest_version": 2,
  "name": "Yahoo Wider Mail",
  "version": "1.1",
  "description": "Various improvements/fixes for Yahoo Mail",
  "author": "def00111",
  "icons": {
    "64": "icons/yahoo.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.yahoo.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content/content.js"
      ],
      "css": [
        "content/content.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c47bac34-849a-4d28-be41-549b2c76c64e}",
      "strict_min_version": "127.0"
    }
  }
}