Examine source code of Simple Motivational Tab

{
  "manifest_version": 2,
  "name": "Simple Motivational Tab",
  "description": "Opens five images with a motivational quote, in new tab",
  "homepage_url": "https://github.com/nabendu82/Addons",
  "version": "1.0",
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png"
  },
  "chrome_url_overrides": {
    "newtab": "tabs.html"
  },
  "applications": {
    "gecko": {
      "strict_min_version": "55.0a2"
    }
  }
}