Edit in JSFiddle

var viewModel = kendo.observable({
    items: ["item1", "item2", "item3"],
    newItem: null,
    add: function(e) {
        if (this.get("newItem")) {
            this.get("items").push(this.get("newItem"));
        }
    }
});

kendo.bind(document.body, viewModel);
<label for="newItem">Enter A New Item</input>
        <input id="newItem" data-bind="value: newItem" class="k-input" />
        <button class="k-button" data-bind="click: add">Add Item</button>
        
        <div id="repeater"></div>
        
        <div data-role="repeater" data-bind="source: items" data-template="template"></div>
        
        <script type="text/x-kendo-template" id="template">
            <div style="color: salmon; margin-right: 10px'"><h1>#= data #</h1></div>
        </script>