Examine source code of Desocialize Media

{
  "manifest_version": 2,
  "name": "Desocialize Media",
  "version": "1.0",
  "description": "Remove comments from social media platforms main feeds.",
  "icons": {
    "48": "icons/mute-48.png",
    "64": "icons/mute-64.png",
    "128": "icons/mute-128.png",
    "512": "icons/mute-512.png"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.facebook.com/*",
        "*://*.instagram.com/*"
      ],
      "js": [
        "desocialize.js"
      ]
    }
  ]
}