[TASK] add quick search index

templates/static/app.js

@@ -2,8 +2,39 @@ document.addEventListener("DOMContentLoaded", function () {
     changeTheme();
     initcolorTheme();
     apply_stickies();
+    initSearch();
 });
 
+function initSearch() {
+  const input = document.querySelector('#filter-js');
+
+  if(input) {
+    filterElements(input.value);
+
+    input.addEventListener('input', () => {
+      filterElements(input.value);
+    });
+  }
+}
+
+function filterElements(input) {
+  const elements = document.querySelectorAll('[data-filterable="true"]');
+
+  Array.prototype.forEach.call(elements, (element) => {
+    // set both strings (input & dataset filter) to lowercase to not be case sensitive
+    let filterString = element.dataset.filter?.toLocaleLowerCase();
+    
+    // bulk hide all elements
+    element.style.display = 'none';
+
+    // show if input matches
+    if(filterString?.includes(input.toLocaleLowerCase())) {
+      element.style.display = 'flex';
+    }
+  });
+}  
+
+
 function changeTheme() {
     let toggleBtn = document.querySelector("#theme-toggle-js");