Examine source code of searchgiggle-search

{
  "manifest_version": 2,
  "name": "searchgiggle-search",
  "version": "0.1",
  "author": "VAL-U-PRO",
  "description": "Perform a search on searchgiggle.com based on the highlighted text",
  "icons": {
    "48": "icons/border-48.png"
  },
  "permissions": [
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}