how to use $compile in angular code example

Example: compile angularjs template

angular.module("myModule", [])
                .controller("myController", ['$scope', '$compile', function ($scope, $compile) {
                    $scope.txt = "<b>SampleTxt</b>";
                    $scope.submit = function () {
                        var html = $compile($scope.txt)($scope);
                        angular.element(document.getElementById("display")).append(html);
                    }
                }]);

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<body ng-app="myModule" >
    <div ng-controller="myController">
        <textarea ng-model="txt" ></textarea>
        <input type="button" value="submit" ng-click="submit()" />
        <div id="display"></div>
    </div>
</body>