Examine source code of DuSubs: Dual Language Subs

{
  "manifest_version": 2,
  "name": "Dusubs",
  "version": "1.2.3",
  "description": "Dual subtitles with pinyin, descriptions, and saving to lists",
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "webRequest",
    "https://www.dusubs.com/*",
    "https://dusubs.com/*",
    "*://*.youtube.com/*",
    "*://*.bilibili.com/*",
    "*://*.bilivideo.com/*"
  ],
  "background": {
    "scripts": [
      "src/background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "world": "MAIN",
      "matches": [
        "https://www.youtube.com/*",
        "https://m.youtube.com/*"
      ],
      "js": [
        "src/youtube-main.js"
      ]
    },
    {
      "world": "MAIN",
      "matches": [
        "https://www.bilibili.com/*"
      ],
      "js": [
        "src/bilibili-main.js"
      ]
    },
    {
      "world": "ISOLATED",
      "matches": [
        "https://www.youtube.com/*",
        "https://m.youtube.com/*",
        "https://www.bilibili.com/*"
      ],
      "js": [
        "vendor/pinyin-pro.js",
        "vendor/kuromoji.js",
        "src/content.bundle.js"
      ]
    },
    {
      "world": "ISOLATED",
      "matches": [
        "https://www.dusubs.com/*",
        "https://dusubs.com/*"
      ],
      "js": [
        "src/web-bridge.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "dusubs@dusubs.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "icons": {
    "512": "assets/icon.png"
  },
  "browser_action": {
    "default_popup": "src/popup.html",
    "default_title": "Hanzi Pinyin Subtitles",
    "default_icon": {
      "512": "assets/icon.png"
    }
  },
  "web_accessible_resources": [
    "vendor/cedict.json.gz",
    "vendor/ja-dict.json.gz",
    "dict/base.dat.gz",
    "dict/check.dat.gz",
    "dict/tid.dat.gz",
    "dict/tid_pos.dat.gz",
    "dict/tid_map.dat.gz",
    "dict/unk.dat.gz",
    "dict/unk_pos.dat.gz",
    "dict/unk_map.dat.gz",
    "dict/unk_char.dat.gz",
    "dict/unk_compat.dat.gz",
    "dict/unk_invoke.dat.gz",
    "dict/cc.dat.gz"
  ]
}