Examine source code of Strongbox AutoFill

{
  "manifest_version": 2,
  "name": "Strongbox AutoFill",
  "version": "1.2.3",
  "icons": {
    "128": "assets/icons/app-icon-blue-128.png"
  },
  "description": "Strongbox Browser AutoFill Extension",
  "short_name": "Strongbox",
  "permissions": [
    "tabs",
    "nativeMessaging",
    "<all_urls>",
    "webNavigation",
    "storage"
  ],
  "author": "Phoebe Code Limited",
  "background": {
    "scripts": [
      "js/background.bundle.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "strongbox@phoebecode.com"
    }
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "128": "assets/icons/app-icon-blue-128.png"
    },
    "default_title": "Strongbox",
    "default_popup": "popup.html"
  },
  "web_accessible_resources": [
    "assets/icons/app-icon-circle.png"
  ],
  "commands": {
    "autofill-first": {
      "suggested_key": {
        "default": "Ctrl+Shift+L"
      },
      "description": "AutoFill"
    },
    "open-inline-menu": {
      "suggested_key": {
        "default": "Ctrl+Shift+O"
      },
      "description": "Show Inline Menu"
    }
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "js/content.bundle.js"
      ],
      "css": [
        "content.css"
      ]
    }
  ]
}