Examine source code of Flashcard Mini

{
  "manifest_version": 2,
  "name": "Flashcard Mini",
  "version": "1.0",
  "description": "Highlight words to create flashcards and review them on new tab.",
  "permissions": [
    "storage",
    "activeTab",
    "contextMenus",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "browser_action": {
    "default_title": "Flashcard Mini"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bd39eda8-275c-410e-943c-36081d38ae0c}"
    }
  }
}