Examine source code of Link Highlighter (MV2)

{
  "manifest_version": 2,
  "name": "Link Highlighter (MV2)",
  "version": "1.0.1",
  "description": "Highlight and count links on the current page on demand. Runs only when you click the toolbar button and stores preferences in Firefox Sync.",
  "icons": {
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4f67ce59-e449-4f7a-9a34-85a8e4cc52b9}",
      "strict_min_version": "91.0"
    }
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Link Highlighter",
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon-48.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  }
}