Examine source code of fixmylayout

{
  "manifest_version": 2,
  "name": "fixmylayout",
  "version": "1.5.3",
  "description": "Simple wrong layout switcher.",
  "icons": {
    "16": "icons/icon_small_dark.svg",
    "32": "icons/icon_small.svg",
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "background": {
    "scripts": [
      "dist/background.js"
    ]
  },
  "permissions": [
    "contextMenus",
    "activeTab",
    "clipboardRead",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "dist/tab.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icons/icon_small_dark.svg",
    "default_title": "fixmylayout",
    "default_popup": "dist/index.html",
    "theme_icons": [
      {
        "light": "icons/icon_small_light.svg",
        "dark": "icons/icon_small_dark.svg",
        "size": 16
      }
    ]
  },
  "web_accessible_resources": [
    "imgs/close.svg"
  ],
  "applications": {
    "gecko": {
      "id": "fixmylayout@nik9"
    }
  },
  "commands": {
    "fix_input_layout": {
      "suggested_key": {
        "default": "Shift+Alt+V"
      },
      "description": "Исправить раскладку в поле ввода"
    }
  }
}