Examine source code of Firefox Relay

{
  "manifest_version": 2,
  "name": "Firefox Relay",
  "version": "2.8.1",
  "description": "__MSG_extensionDescription_mask__",
  "default_locale": "en",
  "icons": {
    "16": "icons/icon_16.png",
    "48": "icons/icon_48.png",
    "96": "icons/icon_96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "private-relay@firefox.com",
      "strict_min_version": "79.0"
    },
    "gecko_android": {
      "id": "private-relay@firefox.com",
      "strict_min_version": "113.0"
    }
  },
  "background": {
    "scripts": [
      "js/libs/browser-polyfill.min.js",
      "js/shared/utils.js",
      "js/background/background.js",
      "js/background/context-menu.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "32": "icons/icon_32.png"
    },
    "default_popup": "popup.html",
    "default_area": "navbar"
  },
  "content_scripts": [
    {
      "matches": [
        "https://relay.firefox.com/"
      ],
      "js": [
        "js/libs/browser-polyfill.min.js",
        "js/relay.firefox.com/track_logout.js"
      ]
    },
    {
      "matches": [
        "https://relay.firefox.com/**"
      ],
      "js": [
        "js/libs/browser-polyfill.min.js",
        "js/relay.firefox.com/inject_addon_data.js"
      ]
    },
    {
      "matches": [
        "https://relay.firefox.com/**"
      ],
      "css": [
        "css/relay-website.css"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://relay.firefox.com/accounts/profile/**"
      ],
      "js": [
        "js/libs/browser-polyfill.min.js",
        "js/relay.firefox.com/get_profile_data.js"
      ]
    },
    {
      "matches": [
        "https://relay.firefox.com/accounts/settings/**"
      ],
      "js": [
        "js/libs/browser-polyfill.min.js",
        "js/relay.firefox.com/settings_refresh.js"
      ]
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/libs/browser-polyfill.min.js",
        "js/shared/utils.js",
        "js/other-websites/fathom.js",
        "js/other-websites/email_detector.js",
        "js/other-websites/icon.js",
        "js/other-websites/fill_relay_address.js",
        "js/shared/metrics.js"
      ],
      "css": [
        "css/relay.css"
      ],
      "all_frames": true
    }
  ],
  "permissions": [
    "<all_urls>",
    "storage",
    "menus",
    "contextMenus"
  ],
  "web_accessible_resources": [
    "images/*.svg",
    "icons/*.svg",
    "icons/*.png",
    "fonts/Inter/*.woff2",
    "fonts/Metropolis/*.woff2",
    "*.html"
  ]
}