Examine source code of UniGlyphs

{
  "manifest_version": 2,
  "name": "UniGlyphs",
  "description": "UniGlyphs lets you format text on any website using an inline toolbar.",
  "version": "0.2.3",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{054bcffe-9644-470b-82fe-640f762a322d}"
    }
  },
  "browser_action": {
    "default_title": "UniGlyphs",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.facebook.com/*",
        "*://*.instagram.com/*",
        "*://*.linkedin.com/*",
        "*://*.messenger.com/*",
        "*://*.quora.com/*",
        "*://*.reddit.com/*",
        "*://*.tiktok.com/*",
        "*://*.tumblr.com/*",
        "*://*.twitter.com/*",
        "*://*.x.com/*",
        "*://*.youtube.com/*"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "content-scripts/content.css"
  ]
}