fix indent and put submit on enter

templates/demo/app/components/blockchain.js

@@ -19,6 +19,14 @@ class Blockchain extends React.Component {
     this.setState({ valueSet: e.target.value });
   }
 
+  checkEnter(e, func) {
+    if (e.key !== 'Enter') {
+      return;
+    }
+    e.preventDefault();
+    func.apply(this, [e]);
+  }
+
   setValue(e) {
     e.preventDefault();
 
@@ -56,14 +64,15 @@ class Blockchain extends React.Component {
   render() {
     return (<React.Fragment>
         <h3> 1. Set the value in the blockchain</h3>
-          <Form inline>
+        <Form inline onKeyDown={(e) => this.checkEnter(e, this.setValue)}>
           <FormGroup>
             <FormControl
               type="text"
               defaultValue={this.state.valueSet}
               onChange={(e) => this.handleChange(e)}/>
             <Button bsStyle="primary" onClick={(e) => this.setValue(e)}>Set Value</Button>
-              <HelpBlock>Once you set the value, the transaction will need to be mined and then the value will be updated on the blockchain.</HelpBlock>
+            <HelpBlock>Once you set the value, the transaction will need to be mined and then the value will be updated
+              on the blockchain.</HelpBlock>
           </FormGroup>
         </Form>