Examine source code of Shade

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "23.8.7.1754",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "69.0",
      "id": "{28694bea-b1a8-4738-a9e1-3af78ad9e9ce}"
    }
  },
  "permissions": [
    "activeTab",
    "contextMenus",
    "storage",
    "http://*/*",
    "https://*/*",
    "tabs"
  ],
  "icons": {
    "16": "icons/shade-16.png",
    "32": "icons/shade-32.png",
    "48": "icons/shade-48.png",
    "64": "icons/shade-64.png",
    "96": "icons/shade-96.png",
    "128": "icons/shade-128.png",
    "256": "icons/shade-256.png",
    "512": "icons/shade-512.png"
  },
  "page_action": {
    "default_icon": {
      "16": "icons/shade-16.png",
      "32": "icons/shade-32.png",
      "48": "icons/shade-48.png",
      "64": "icons/shade-64.png",
      "96": "icons/shade-96.png",
      "128": "icons/shade-128.png",
      "256": "icons/shade-256.png",
      "512": "icons/shade-512.png"
    },
    "default_title": "__MSG_menuItemMask__",
    "pinned": true,
    "show_matches": [
      "http://*/*",
      "https://*/*"
    ]
  },
  "background": {
    "persistent": false,
    "scripts": [
      "browser-polyfill.min.js",
      "background.js"
    ]
  },
  "commands": {
    "shade-down": {
      "suggested_key": {
        "default": "Ctrl+Shift+7",
        "windows": "Ctrl+Shift+1",
        "mac": "MacCtrl+Shift+7"
      },
      "description": "Lower the shade in the current tab"
    },
    "shade-up": {
      "suggested_key": {
        "default": "Ctrl+Shift+8",
        "windows": "Ctrl+Shift+2",
        "mac": "MacCtrl+Shift+8"
      },
      "description": "Raise the shade in the current tab"
    },
    "shade-down-all": {
      "suggested_key": {
        "default": "Ctrl+Shift+9",
        "windows": "Ctrl+Shift+3",
        "mac": "MacCtrl+Shift+9"
      },
      "description": "Lower the shade in all tabs in the current window"
    },
    "shade-up-all": {
      "suggested_key": {
        "default": "Ctrl+Shift+0",
        "windows": "Ctrl+Shift+4",
        "mac": "MacCtrl+Shift+0"
      },
      "description": "Raise the shade in all tabs in the current window"
    }
  },
  "web_accessible_resources": [
    "mask.css"
  ]
}