Examine source code of HackBar Quantum

{
  "manifest_version": 2,
  "name": "HackBar Quantum",
  "description": "HackBar Quantum is a sidebar that assists you with web application security testing, it's aim is to help make those tedious tasks a little bit easier. This add-on is a predecessor to the original HackBar that is not compatible with Firefox Quantum.",
  "version": "1.6",
  "applications": {
    "gecko": {
      "strict_min_version": "57.0"
    }
  },
  "author": "DLS",
  "developer": {
    "name": "DLS",
    "url": "http://twitter.com/totallynotdls"
  },
  "homepage_url": "https://github.com/notdls/hackbar",
  "icons": {
    "48": "icons/hackbar_48.png"
  },
  "sidebar_action": {
    "default_icon": "icons/hackbar_48.png",
    "default_title": "HackBar Quantum",
    "default_panel": "hackbar/hackbar.html"
  },
  "background": {
    "scripts": [
      "hackbar/background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/hackbar_16.png",
      "32": "icons/hackbar_32.png",
      "48": "icons/hackbar_48.png"
    }
  },
  "permissions": [
    "storage",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "commands": {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "F9"
      }
    }
  }
}