Examine source code of d-Record

{
  "manifest_version": 2,
  "name": "d-Record",
  "description": "dアニメストア・ABEMAで見たアニメを自動で記録します。",
  "version": "2.3.5",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "storage",
    "identity",
    "activeTab",
    "https://api.annict.com/graphql",
    "https://animestore.docomo.ne.jp/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{32acf05e-234c-4a49-98ca-47c15d23a51f}",
      "strict_min_version": "115.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "d-Record設定",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://abema.tv/*",
        "https://animestore.docomo.ne.jp/animestore/ci_pc*",
        "https://animestore.docomo.ne.jp/animestore/sc_d_pc*"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "content-scripts/content.css"
  ]
}