Examine source code of BlackMagic.so Extension

{
  "manifest_version": 2,
  "name": "BlackMagic.so Extension",
  "version": "3.6.0",
  "icons": {
    "16": "assets/icons/favicon-16.png",
    "32": "assets/icons/favicon-32.png",
    "48": "assets/icons/favicon-48.png",
    "128": "assets/icons/favicon-128.png"
  },
  "description": "Magic Sidebar by BlackMagic.so",
  "homepage_url": "https://blackmagic.so/sidebar/",
  "short_name": "BlackMagic.so Extension",
  "permissions": [
    "https://twitter.com/*",
    "https://mobile.twitter.com/*"
  ],
  "web_accessible_resources": [
    "frame.html",
    "js/frame.bundle.js"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "author": "tdinh_me",
  "applications": {
    "gecko": {
      "id": "{A8C765C9-B229-47E6-B88D-7B1ED80BD553}"
    }
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icons/favicon-16.png",
      "32": "assets/icons/favicon-32.png",
      "48": "assets/icons/favicon-48.png",
      "128": "assets/icons/favicon-128.png"
    },
    "default_title": "BlackMagic.so",
    "browser_style": false
  },
  "background": {
    "scripts": [
      "js/background.bundle.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*",
        "https://mobile.twitter.com/*"
      ],
      "js": [
        "js/contentScript.bundle.js"
      ],
      "css": [
        "css/contentScript.css"
      ]
    }
  ]
}