Examine source code of PJO to Anki

{
  "manifest_version": 2,
  "name": "PJO to Anki",
  "version": "0.1.2",
  "icons": {
    "16": "assets/icons/favicon_16.png",
    "32": "assets/icons/favicon_32.png",
    "48": "assets/icons/favicon_48.png",
    "128": "assets/icons/favicon_128.png"
  },
  "web_accessible_resources": [
    "assets/icons/*",
    "css/*"
  ],
  "description": "Adiciona um botão para automatizar a criação de cartas no Anki à partir das frases do site.",
  "homepage_url": "https://github.com/SecretX/pjo-to-anki",
  "short_name": "PJO to Anki",
  "permissions": [
    "storage"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "author": "SecretX",
  "applications": {
    "gecko": {
      "id": "{6c18edec-5854-4df8-980b-816befc39d55}"
    }
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icons/favicon_16.png",
      "32": "assets/icons/favicon_32.png",
      "48": "assets/icons/favicon_48.png",
      "128": "assets/icons/favicon_128.png"
    },
    "default_title": "PJO to Anki",
    "browser_style": false
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "js/background.js"
    ],
    "persistent": false,
    "type": "module"
  },
  "content_scripts": [
    {
      "run_at": "document_start",
      "matches": [
        "https://portal.programajaponesonline.com.br/*"
      ],
      "css": [
        "css/vanillatoasts.min.css",
        "css/contentScript.css"
      ],
      "js": [
        "js/vanillatoasts.min.js"
      ]
    },
    {
      "run_at": "document_end",
      "matches": [
        "https://portal.programajaponesonline.com.br/*"
      ],
      "js": [
        "js/contentScript.js"
      ]
    }
  ]
}