Examine source code of MorseFire

{
  "manifest_version": 2,
  "name": "MorseFire",
  "description": "Play text selections as morse code",
  "homepage_url": "https://github.com/dancrew32/morsefire",
  "version": "0.3",
  "icons": {
    "48": "icons/icon.png",
    "96": "icons/icon@2x.png"
  },
  "permissions": [
    "contextMenus",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "jscwlib.js",
        "morsefire.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "chrome_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5abac8f8-22a0-46b2-837e-32f46c33fe53}"
    }
  }
}