Examine source code of Open with Selection

{
  "author": "igorlogius",
  "homepage_url": "https://github.com/igorlogius/open-with-selection",
  "description": "Open tabs with placeholder URLs and selected text",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_area": "navbar",
    "default_popup": "options.html"
  },
  "commands": {
    "open": {
      "description": "Open selection with enabled placeholder",
      "suggested_key": {
        "default": "F1"
      }
    }
  },
  "icons": {
    "128": "icon.png"
  },
  "manifest_version": 2,
  "name": "Open With Selection",
  "permissions": [
    "<all_urls>",
    "menus",
    "storage"
  ],
  "version": "1.4.16",
  "browser_specific_settings": {
    "gecko": {
      "id": "{aa55b819-9d9e-4220-b9f7-7cabd727c123}"
    }
  }
}