Examine source code of Context Play/ Pause

{
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "strict_min_version": "60.0",
      "id": "{a5139d9c-a7bf-4725-97c8-c05fb1fa3660}"
    }
  },
  "name": "Context Play/ Pause",
  "version": "1.1resigned1",
  "description": "Play and pause videos from the tab context menu",
  "icons": {
    "48": "icons/play-pause-48.png",
    "96": "icons/play-pause-96.png"
  },
  "permissions": [
    "*://*/*",
    "menus",
    "activeTab",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}