Examine source code of ff-lucid

{
  "name": "FFLucid",
  "version": "2.1.0",
  "manifest_version": 2,
  "description": "Replace your new tab page with a simple notepad and greeting.",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "default_locale": "en",
  "chrome_url_overrides": {
    "newtab": "src/override/override.html"
  },
  "chrome_settings_overrides": {
    "homepage": "src/override/override.html"
  },
  "options_ui": {
    "page": "src/options/options.html",
    "browser_style": false,
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "fflucid@fflucid.com",
      "strict_min_version": "48.0"
    }
  },
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  }
}