Examine source code of Super Refresh

{
  "manifest_version": 2,
  "name": "Super Refresh",
  "version": "1.1.1",
  "description": "Refresh all the tabs!  Click on the extension icon or use the keyboard shortcut to reload all open tabs in the current window.",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {},
  "commands": {
    "refreshAll": {
      "suggested_key": {
        "default": "Shift+Ctrl+5"
      },
      "description": "Refresh all the tabs!"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "permissions": [
    "storage"
  ]
}