Examine source code of Click to Outline!

{
  "manifest_version": 2,
  "name": "Click to Outline!",
  "description": "Open pages via Outline with a click.",
  "author": "apsvieira",
  "version": "1.1.0",
  "homepage_url": "https://gitlab.com/apsvieira/click-to-outline",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "tabs",
    "contextMenus"
  ],
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "Click to Outline!"
  },
  "background": {
    "scripts": [
      "node_modules/webextension-polyfill/dist/browser-polyfill.js",
      "outline.js"
    ]
  }
}