Examine source code of Ad Mute

{
  "manifest_version": 3,
  "name": "Ad Mute",
  "version": "1.4.1",
  "description": "Mutes the player when ads are playing and skips them when possible. (Twitch, YouTube)",
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "host_permissions": [
    "*://*.twitch.tv/*",
    "*://*.youtube.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.twitch.tv/*"
      ],
      "js": [
        "twitch.js"
      ]
    },
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "youtube.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{85156fa3-c5e3-44ba-988a-3a07c1487398}"
    }
  }
}