Examine source code of Rage Button

{
  "manifest_version": 2,
  "name": "Rage Button",
  "version": "0.1.1",
  "description": "Adds a button that really brings out the rage.",
  "applications": {
    "gecko": {
      "id": "ragebutton@julian-fietkau.de",
      "strict_min_version": "60.0"
    }
  },
  "icons": {
    "1960": "button.svg"
  },
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "button.svg",
    "default_title": "AAAAAAAAA!"
  }
}