text: var MODULE = (function (app) {
      const columns = 3; /* grid columns */
      const grindLength = 12; /* grid items */
      var itemWidth;
  
      window.addEventListener("load", function() {
          var gridContainer = document.getElementById('generatedGrid');
          itemWidth = (100 / columns).toFixed(2);
          populateGrid(gridContainer);
      })
  
      function populateGrid (container) {
          for (let i = 0; i < grindLength; i++) {
              // calculate tabIndex
              var row = 10 * Math.floor(i / columns);
              var ti = row + i%columns;
  
              var entry = document.createElement("div");
              entry.className = 'navItem';
              entry.tabIndex = ti;
              entry.style.width = itemWidth+'%';
              entry.setAttribute('data-function','changeColor');
  
              var headline = document.createElement("h3");
              headline.innerText = i;
              entry.appendChild(headline);
  
              var content = document.createElement("span");
              content.innerText = 'tI: '+ ti;
              entry.appendChild(content);
  
              container.appendChild(entry);
          }
      }
      
      return app;
  }(MODULE));