Examine source code of Sidebar Toggle

{
  "manifest_version": 3,
  "name": "Sidebar Toggle",
  "short_name": "Sidebar",
  "description": "Hide sidebars/top bars on old Reddit, YouTube and GitHub to reclaim screen space. Plus a YouTube cinema-dim mode.",
  "version": "1.0.3",
  "author": "Sinan Midillili",
  "homepage_url": "https://github.com/sinanm89/Sidebar-Toggle",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_title": "Sidebar Toggle",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png"
    }
  },
  "background": {
    "scripts": [
      "sites.js",
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "scripting",
    "activeTab"
  ],
  "host_permissions": [
    "*://old.reddit.com/*",
    "*://www.youtube.com/*",
    "*://github.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://old.reddit.com/*",
        "*://www.youtube.com/*",
        "*://github.com/*"
      ],
      "js": [
        "sites.js",
        "engine.js",
        "content.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "commands": {
    "toggle-sidebar": {
      "suggested_key": {
        "default": "Ctrl+Shift+E",
        "mac": "Command+Shift+E"
      },
      "description": "Toggle the sidebar / top bar on the current supported site"
    },
    "toggle-theater": {
      "suggested_key": {
        "default": "Alt+E",
        "mac": "Alt+E"
      },
      "description": "YouTube only: toggle cinema dim (spotlight the player)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "sidebar-toggle@sinanm89.github.io",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}