Add category filter for skills (#979)

Co-authored-by: Emruz Hossain <hossainemruz@gmail.com>

assets/scripts/sections/index.js

@@ -4,4 +4,5 @@ import './sidebar'
 import './education'
 import './achievements'
 import './projects'
+import './skills'
 import './publications'

assets/scripts/sections/skills.js

@@ -0,0 +1,15 @@
+import Filterizr from 'filterizr'
+
+document.addEventListener('DOMContentLoaded', () => {
+  // ================== Skill cards =====================
+
+  // setup skill filter buttons
+  const skillCardHolder = document.getElementById('skill-card-holder')
+  if (skillCardHolder != null && skillCardHolder.children.length !== 0) {
+    // eslint-disable-next-line no-new
+    new Filterizr('.filtr-skills', {
+      layout: 'sameWidth',
+      controlsSelector: '.skill-filtr-control'
+    })
+  }
+})