Examine source code of Highlighter SEO

{
  "manifest_version": 3,
  "name": "Highlighter SEO",
  "version": "4.1",
  "description": "SEO tool to help visualize page structure titles, paragraphs and image alt. It also helps to verify the correct design of a web page",
  "browser_specific_settings": {
    "gecko": {
      "id": "{334b0108-6476-4283-bec1-9392a9a1dd24}",
      "strict_min_version": "115.0"
    }
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "Highlighter SEO"
  },
  "permissions": [
    "activeTab",
    "scripting",
    "tabs",
    "webRequest",
    "storage"
  ],
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "sidebar_action": {
    "default_panel": "popup.html",
    "default_title": "Highlighter SEO",
    "default_icon": {
      "16": "Button-Icons/icon.png",
      "48": "Button-Icons/icon.png"
    },
    "open_at_install": false
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "stopwords.js",
        "content.js"
      ],
      "css": [
        "content-styles.css"
      ]
    }
  ],
  "icons": {
    "16": "Button-Icons/icon.png",
    "48": "Button-Icons/icon.png",
    "128": "Button-Icons/icon.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "serp-results.html",
        "serp-results.js",
        "serp-results.css",
        "i18n.js",
        "styles.css",
        "upload.html",
        "upload.js",
        "Button-Icons/*",
        "audio-cat/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}