Examine source code of Better FF Reader

{
  "manifest_version": 2,
  "author": "Isaac Khor",
  "name": "Better FF Reader",
  "version": "0.2.1resigned1",
  "description": "A better version of the built-in reader mode",
  "homepage_url": "https://github.com/ClarenceClark/better-ff-reader",
  "icons": {
    "48": "icons/icon.svg"
  },
  "permissions": [
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "applications": {
    "gecko": {
      "id": "d.betterffreader@isaackhor.com",
      "strict_min_version": "55.0"
    }
  },
  "page_action": {
    "default_icon": "icons/icon.svg",
    "default_title": "Better reader mode"
  },
  "browser_action": {
    "default_title": "Toggle reader mode",
    "default_icon": "icons/icon.svg"
  },
  "commands": {
    "toggle-reader-mode": {
      "suggested_key": {
        "default": "Ctrl+0"
      },
      "description": "Toggle Reader Mode"
    }
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "web_accessible_resources": [
    "libs/*",
    "css/*"
  ],
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  }
}