Examine source code of Udemy Progress

{
  "manifest_version": 2,
  "name": "Udemy Progress",
  "version": "1.0.1",
  "description": "Calculate your udemy course progress not by number but length of lectures",
  "homepage_url": "https://github.com/burak-yildirim/udemy-progress",
  "icons": {
    "32": "icons/progress-32.png",
    "48": "icons/progress-48.png"
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.udemy.com/*/learn/lecture/*"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icons/progress-32.png",
    "default_title": "Udemy Progress",
    "default_popup": "popup/popup.html"
  }
}