Examine source code of Loom

{
  "manifest_version": 2,
  "name": "Loom",
  "description": "Dual subtitles with romanization for foreign-language video on YouTube, Netflix, Prime Video, iQIYI, and WeTV.",
  "version": "0.5.1",
  "icons": {
    "16": "icons/prod/16.png",
    "32": "icons/prod/32.png",
    "48": "icons/prod/48.png",
    "96": "icons/prod/96.png",
    "128": "icons/prod/128.png"
  },
  "permissions": [
    "storage",
    "webRequest",
    "*://*.youtube.com/*",
    "*://*.netflix.com/*",
    "*://*.nflxvideo.net/*",
    "*://*.iq.com/*",
    "*://*.iqiyi.com/*",
    "*://*.wetv.vip/*",
    "*://*.wetvinfo.com/*",
    "*://*.video.qq.com/*",
    "*://*.myqcloud.com/*",
    "*://*.primevideo.com/*",
    "*://*.pv-cdn.net/*",
    "https://api.loom.nerv-analytic.ai/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "loom@nerv-analytic.ai",
      "data_collection_permissions": {
        "required": [
          "websiteContent"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Loom",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/content.js"
      ]
    },
    {
      "matches": [
        "*://*.iq.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/iqiyi-main.js"
      ],
      "world": "MAIN"
    },
    {
      "matches": [
        "*://*.iq.com/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/iqiyi.js"
      ]
    },
    {
      "matches": [
        "*://*.netflix.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/netflix-main.js"
      ],
      "world": "MAIN"
    },
    {
      "matches": [
        "*://*.netflix.com/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/netflix.js"
      ]
    },
    {
      "matches": [
        "*://*.primevideo.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/prime-main.js"
      ],
      "world": "MAIN"
    },
    {
      "matches": [
        "*://*.primevideo.com/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/prime.js"
      ]
    },
    {
      "matches": [
        "*://*.wetv.vip/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/wetv-main.js"
      ],
      "world": "MAIN"
    },
    {
      "matches": [
        "*://*.wetv.vip/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/wetv.js"
      ]
    },
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/yt-main.js"
      ],
      "world": "MAIN"
    }
  ]
}