Examine source code of Context Searcher

{
  "manifest_version" : 2 ,
  "name" : "Context Searcher",
  "version" : "1.3",
  "description" : "Search for highlighted text on Wikipedia, DuckDuckGo, YouTube, Dict.cc, Urban Dictonary and Stackoverflow from the context menu. Find The source code here: https://github.com/TheOnAndOnlyZenomat/firefox-context-search",
  "background" : {
    "scripts" : [
      "background.js" 
    ]
  },
  "permissions" : [
    "menus" 
  ],
  "icons" : {
    "48" : "icons/icon-48.png"
  }
}