Examine source code of fping

{
  "manifest_version": 2,
  "name": "fping",
  "version": "0.1.0",
  "description": "This extension will remove ping from <a href> tags in html",
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "*://*/*"
      ]
    }
  ],
  "icons": {
    "128": "logo.png"
  },
  "content_security_policy": " default-src 'self'"
}