Examine source code of HyperLegible

{
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "hyper.js"
      ]
    }
  ],
  "manifest_version": 2,
  "browser_action": {
    "default_icon": "icon-128.png",
    "default_title": "HyperLegible"
  },
  "name": "HyperLegible",
  "description": "Makes all fonts on page use Atkinson font",
  "homepage_url": "https://github.com/JakeTrock/HyperLegible",
  "icons": {
    "16": "icon-16.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "web_accessible_resources": [
    "Font/*"
  ],
  "version": "5.0"
}