Examine source code of Quick Emojis

{
  "name": "Quick Emojis for WhatsApp and Messenger",
  "version": "0.0.0.6",
  "description": "One-click reply using your favorite emojis",
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "16": "assets/quick-emojis-logo16.png",
      "32": "assets/quick-emojis-logo32.png",
      "48": "assets/quick-emojis-logo48.png",
      "128": "assets/quick-emojis-logo128.png"
    },
    "default_popup": "src/popup.html"
  },
  "icons": {
    "16": "assets/quick-emojis-logo16.png",
    "32": "assets/quick-emojis-logo32.png",
    "48": "assets/quick-emojis-logo48.png",
    "128": "assets/quick-emojis-logo128.png"
  },
  "web_accessible_resources": [
    "assets/cog-icon.png",
    "assets/quick-emojis-logo48.png",
    "assets/quick-emojis-logo48-whatsapp.png",
    "assets/quick-emojis-logo-name.png",
    "assets/timesIcon.svg",
    "assets/dark-mode-icon.png"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://web.whatsapp.com/"
      ],
      "css": [
        "src/css/styles-whatsapp.css"
      ],
      "js": [
        "src/js/content-script-whatsapp.js"
      ]
    },
    {
      "matches": [
        "https://www.messenger.com/*"
      ],
      "css": [
        "src/css/styles-messenger.css"
      ],
      "js": [
        "src/js/content-script-messenger.js"
      ]
    }
  ],
  "manifest_version": 2
}