Examine source code of Viewbench: Window Resizer & Responsive Bench

{
  "manifest_version" : 3 ,
  "name" : "Viewbench: Window Resizer & Responsive Bench",
  "short_name" : "Viewbench",
  "version" : "1.2.0",
  "description" : "Resize to exact viewport sizes with unlimited presets and shortcuts, and test one page on several devices side by side.",
  "icons" : {
    "16" : "icons/icon16.png",
    "32" : "icons/icon32.png",
    "48" : "icons/icon48.png",
    "128" : "icons/icon128.png"
  },
  "action" : {
    "default_title" : "Viewbench",
    "default_popup" : "popup.html",
    "default_icon" : {
      "16" : "icons/icon16.png",
      "32" : "icons/icon32.png"
    }
  },
  "background" : {
    "scripts" : [
      "config.js" ,
      "lib/core.js" ,
      "lib/licence.js" ,
      "background.js" 
    ]
  },
  "permissions" : [
    "storage" ,
    "scripting" ,
    "declarativeNetRequestWithHostAccess" 
  ],
  "optional_host_permissions" : [
    "https://*/*" ,
    "http://*/*" 
  ],
  "commands" : {
    "next-preset": {
      "suggested_key": {
        "default": "Alt+Shift+Right"
      },
      "description" : "Next preset"
    },
    "prev-preset": {
      "suggested_key": {
        "default": "Alt+Shift+Left"
      },
      "description" : "Previous preset"
    },
    "rotate": {
      "suggested_key": {
        "default": "Alt+Shift+Up"
      },
      "description" : "Rotate (swap width and height)"
    },
    "open-bench": {
      "suggested_key": {
        "default": "Alt+Shift+B"
      },
      "description" : "Open this page on the bench"
    },
    "preset-1": {
      "description" : "Preset 1"
    },
    "preset-2": {
      "description" : "Preset 2"
    },
    "preset-3": {
      "description" : "Preset 3"
    },
    "preset-4": {
      "description" : "Preset 4"
    },
    "preset-5": {
      "description" : "Preset 5"
    },
    "preset-6": {
      "description" : "Preset 6"
    },
    "preset-7": {
      "description" : "Preset 7"
    },
    "preset-8": {
      "description" : "Preset 8"
    },
    "preset-9": {
      "description" : "Preset 9"
    },
    "preset-10": {
      "description" : "Preset 10"
    },
    "preset-11": {
      "description" : "Preset 11"
    },
    "preset-12": {
      "description" : "Preset 12"
    }
  },
  "homepage_url" : "https://digivibetech.com/viewbench/",
  "optional_permissions" : [
    "downloads" 
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "viewbench@digivibetech",
      "strict_min_version": "128.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}