Examine source code of Emoji Lens

{
  "manifest_version": 2,
  "name": "Emoji Lens",
  "version": "1.0",
  "description": "Hover over images to see a quick emoji suggestion based on alt/title/src/nearby text.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "48": "icon48.png",
    "96": "icon96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{12b5262d-60ae-483b-9c65-60f4d5a0652d}"
    }
  }
}