Examine source code of Test Fill (V2)

{
  "manifest_version": 2,
  "name": "Test Fill (V2)",
  "version": "2.0",
  "description": "Adds test fill data",
  "icons": {
    "48": "icons/TFV2_48.png",
    "96": "icons/TFV2_96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.mozilla.org/*"
      ],
      "js": [
        "content-scripts/test-fill.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "storage",
    "http://*/*",
    "https://*/*"
  ],
  "browser_action": {
    "default_popup": "popup/test-fill.html"
  },
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true,
    "chrome_style": true,
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "stuart_wilcox@outlook.com"
    }
  }
}