Examine source code of Tab Deque

{
  "action": {
    "default_icon": "icon.svg",
    "default_popup": "options/options.html",
    "default_title": "Tab Deque"
  },
  "author": "Sebastian Blask",
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "tabdeque@sblask"
    }
  },
  "commands": {
    "select-tab-from-end-of-tabdeque": {
      "description": "Select tab from end of TabDeque",
      "suggested_key": {
        "default": "Ctrl+Up"
      }
    },
    "send-tab-to-end-of-tabdeque": {
      "description": "Send tab to end of TabDeque",
      "suggested_key": {
        "default": "Ctrl+Down"
      }
    },
    "toggle-add-background-tabs-after-current-option": {
      "description": "Toggle `Insert new tabs into TabDeque after current tabs` option",
      "suggested_key": {
        "default": "Ctrl+Shift+I"
      }
    }
  },
  "description": "A webextension for better tab handling. Inspired by Opera 12.",
  "homepage_url": "https://github.com/sblask/webextension-tab-deque",
  "icons": {
    "48": "icon.svg"
  },
  "manifest_version": 3,
  "name": "Tab Deque",
  "options_ui": {
    "page": "options/options.html"
  },
  "permissions": [
    "contextMenus",
    "storage"
  ],
  "version": "3.1.0"
}