Examine source code of Alias Email

{
  "name": "Alias Email - Free Email Aliases",
  "author": "Bump Team",
  "manifest_version": 2,
  "homepage_url": "https://alias.email",
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png",
    "256": "icons/icon-256.png",
    "512": "icons/icon-512.png",
    "1024": "icons/icon-1024.png"
  },
  "background": {
    "scripts": [
      "./js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "exclude_matches": [
        "https://*.alias.email/*"
      ],
      "js": [
        "js/content-script.js"
      ],
      "all_frames": true,
      "match_about_blank": true
    },
    {
      "matches": [
        "https://*.alias.email/*"
      ],
      "js": [
        "js/content-script-internal.js"
      ]
    }
  ],
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "windows": "Ctrl+Shift+Y",
        "mac": "Command+Shift+Y"
      }
    }
  },
  "permissions": [
    "storage",
    "tabs",
    "contextMenus",
    "https://alias.email/*",
    "https://www.google-analytics.com/*"
  ],
  "web_accessible_resources": [
    "css/*.css",
    "fonts/*.woff2",
    "*.png"
  ],
  "version": "2.1.5",
  "description": "Hide your real email and control who can send you messages. Generate new emails with one click is pretty easy.",
  "browser_specific_settings": {
    "gecko": {
      "id": "extension@bump.email"
    }
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "20": "icons/icon-20.png",
      "24": "icons/icon-24.png",
      "32": "icons/icon-32.png",
      "40": "icons/icon-40.png"
    },
    "default_popup": "./popup.html",
    "default_title": "Alias Email - Free Email Aliases"
  }
}