Examine source code of select2decode

{
  "manifest_version": 2,
  "name": "select2decode",
  "description": "select base64 text to decode",
  "icons": {
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "author": "zbinlin",
  "homepage_url": "https://github.com/zbinlin",
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "css": [
        "stylesheets/content.css"
      ],
      "js": [
        "javascripts/content.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "background": {
    "persistent": false,
    "scripts": [
      "javascripts/background.js"
    ]
  },
  "permissions": [
    "contextMenus"
  ],
  "version": "1.0.4resigned1",
  "applications": {
    "gecko": {
      "id": "{d4d3b34f-0f12-4a00-8663-e8efb691f13a}"
    }
  }
}