Examine source code of TypeQuicker

{
  "manifest_version": 2,
  "name": "TypeQuicker",
  "version": "1.0.0",
  "description": "Practice typing with any highlighted text on the web. Browser extension by TypeQuicker.",
  "permissions": [
    "contextMenus",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "modal.css"
      ]
    }
  ],
  "web_accessible_resources": [
    "modal.html",
    "modal.css",
    "modal.js",
    "icons/128.png"
  ],
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{30be2c39-6963-49ff-88a1-a9a6c91028f4}"
    }
  }
}