Examine source code of meta::cpan::theme

{
  "name": "meta::cpan::theme",
  "browser_specific_settings": {
    "gecko": {
      "id": "email@lnation.org"
    }
  },
  "version": "2.8",
  "description": "theme meta::cpan to your taste",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "options_ui": {
    "page": "theme.html",
    "open_in_tab": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.metacpan.org/*"
      ],
      "run_at": "document_start",
      "js": [
        "js/theme.js",
        "js/content.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "theme.html",
    "default_icon": {
      "16": "images/meta-16.png",
      "32": "images/meta-32.png",
      "48": "images/meta-48.png",
      "128": "images/meta-128.png"
    }
  },
  "icons": {
    "16": "images/meta-16.png",
    "32": "images/meta-32.png",
    "48": "images/meta-48.png",
    "128": "images/meta-128.png"
  },
  "web_accessible_resources": [
    "images/metacpan-white-logo.png",
    "images/metacpan-logo.png",
    "images/metacpan-logo-solarize-dark.png",
    "images/metacpan-logo-solarize-light.png",
    "images/metacpan-logo-light.png",
    "images/metacpan-logo.png",
    "images/meta-48.png"
  ],
  "manifest_version": 2
}