Examine source code of MyImgurEmoji

{
  "manifest_version": 2,
  "name": "MyImgurEmoji",
  "description": "Use imgur albums as custom emoji sets on any site",
  "version": "0.1.1",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "jquery-3.4.1.js",
        "common.js",
        "data.js",
        "content.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "activeTab",
    "https://api.imgur.com/3/album/*"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "MyImgurEmoji"
  }
}