Examine source code of Math substitute

{
  "manifest_version": 2,
  "name": "Math substitute",
  "description": "Replaces words with mathfunctions.",
  "version": "1.0",
  "icons": {
    "48": "icons/icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "./emojiMap.js",
        "./substitute.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5e05614a-24d1-4109-a585-3fb7d393507a}"
    }
  }
}