fix: remove dead js code

src/assets/js/index.js

@@ -1,26 +1 @@
 import './nav.js'
-
-class ToggleMenuButton extends HTMLElement {
-    connectedCallback() {
-        this.addEventListener('click', this.onClick.bind(this))
-        const windowsChangeEvent = ('onorientationchange' in window) ? 'orientationchange':'resize';
-        window.addEventListener(windowsChangeEvent, this.close.bind(this))
-    }
-
-    get targetElement() {
-        const targetElementId = this.getAttribute('target')
-        const targetElement = document.getElementById(targetElementId)
-        console.assert(targetElement !== undefined)
-        return targetElement
-    }
-
-    onClick(evt) {
-        this.targetElement.classList.toggle('nav__open')
-        evt.preventDefault()
-    }
-
-    close() {
-        this.targetElement.classList.remone('nav__open')
-    }
-}
-