added playground component

Author: prasanna1211

docs/client/components/PlaygroundPage/PlaygroundWithPreview/Playground.js

@@ -0,0 +1,40 @@
+import React from 'react';
+import Editor from 'codemirror';
+import 'codemirror/lib/codemirror.css';
+import 'codemirror/mode/javascript/javascript';
+
+import styles from './styles.scss';
+
+import './editor.css';
+
+class Playground extends React.Component {
+  constructor(props) {
+    super(props);
+
+  }
+  
+  componentDidMount() {
+    this.editor = Editor.fromTextArea(this.refs.editor, {
+      mode: 'javascript',
+      lineNumbers: false,
+      smartIndent: false,
+      tabSize: 2,
+      matchBrackets: true,
+      theme: 'custom',
+      readOnly: false,
+    });
+  }
+
+  render() {
+    return (
+      <div className={styles.playground}>
+        <textarea
+          ref="editor"
+          defaultValue={this.props.code}
+        />
+      </div>
+    );
+  }
+}
+
+export default Playground;