Examine source code of Mouse Pet

{
  "browser_specific_settings": {
    "gecko": {
      "id": "mousepet@srkomodo.com",
      "strict_min_version": "53.0"
    }
  },
  "manifest_version": 2,
  "version": "1.2.1",
  "name": "Mouse Pet",
  "description": "A fun extension that adds a creature following your cursor",
  "author": "SrKomodo",
  "homepage_url": "https://github.com/SrKomodo/mouse-pet",
  "icons": {
    "16": "icon.svg",
    "32": "icon.svg",
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "inject/inject.js"
      ]
    }
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": "icon.svg",
    "default_popup": "popup/popup.html"
  },
  "options_ui": {
    "page": "popup/popup.html"
  },
  "permissions": [
    "storage"
  ]
}