Examine source code of Tab Positioner

{
  "manifest_version": 2,
  "name": "Tab Positioner",
  "version": "1.0",
  "description": "Places new tabs near their opener or at the beginning of the tab bar if opened normally.",
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ee6368f1-6f86-4252-8f6c-a2f9b913504a}"
    }
  }
}