Examine source code of newTabPosition

{
  "name": "newTabPosition",
  "author": "Terry",
  "version": "0.1",
  "description": "Sets your browser to always open tabs next to the current tab, even for blank tabs.",
  "manifest_version": 2,
  "icons": {
    "24": "icon_24.png",
    "48": "icon_48.png",
    "96": "icon_96.png"
  },
  "applications": {
    "gecko": {
      "strict_min_version": "61.0"
    }
  },
  "permissions": [
    "browserSettings"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  }
}