Examine source code of FireFlashcards

{
  "manifest_version": 2,
  "name": "FireFlashcards",
  "version": "1.0.1",
  "description": "Spaced-repetition flashcards using Firefox Sync storage. Choose your target language (Japanese, Thai, Spanish, Korean, etc.).",
  "applications": {
    "gecko": {
      "id": "fireflashcards@local",
      "strict_min_version": "109.0"
    }
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "browser_action": {
    "default_title": "FireFlashcards",
    "default_icon": "icons/icon.svg",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true
  },
  "permissions": [
    "storage",
    "contextMenus",
    "tabs",
    "activeTab"
  ],
  "commands": {
    "open_popup": {
      "suggested_key": {
        "default": "Alt+Shift+F",
        "mac": "Alt+Shift+F"
      },
      "description": "Open FireFlashcards"
    },
    "quick_add": {
      "suggested_key": {
        "default": "Alt+Shift+A",
        "mac": "Alt+Shift+A"
      },
      "description": "Quick add selected text"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content/content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}