Examine source code of No Distractions

{
  "manifest_version": 2,
  "name": "No Distractions",
  "description": "Removes algorithmic feeds, reels, and endless scrolling — see only posts from people you follow.",
  "version": "0.0.0.1",
  "permissions": [
    "storage",
    "alarms",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "no_distractions_logo.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://m.youtube.com/*"
      ],
      "js": [
        "js/init-class.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://m.youtube.com/*"
      ],
      "css": [
        "css/youtube.css"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://m.youtube.com/*"
      ],
      "js": [
        "js/youtube.js"
      ],
      "all_frames": true,
      "run_at": "document_idle"
    },
    {
      "matches": [
        "https://www.facebook.com/*",
        "https://m.facebook.com/*"
      ],
      "js": [
        "js/init-class.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.facebook.com/*",
        "https://m.facebook.com/*"
      ],
      "css": [
        "css/facebook.css"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.facebook.com/*",
        "https://m.facebook.com/*"
      ],
      "js": [
        "js/facebook.js"
      ],
      "all_frames": true,
      "run_at": "document_idle"
    },
    {
      "matches": [
        "https://www.instagram.com/*"
      ],
      "css": [
        "css/instagram.css"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.instagram.com/*"
      ],
      "js": [
        "js/instagram.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://*.reddit.com/*"
      ],
      "js": [
        "js/init-class.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://*.reddit.com/*"
      ],
      "css": [
        "css/reddit.css"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://*.reddit.com/*"
      ],
      "js": [
        "js/reddit.js"
      ],
      "all_frames": true,
      "run_at": "document_idle"
    }
  ],
  "applications": {
    "gecko": {
      "id": "no-distractions@example.com",
      "strict_min_version": "68.0"
    }
  }
}