fix(aio): trim code blocks before rendering

aio/src/app/embedded/code/code.component.ts

@@ -23,7 +23,7 @@ const copiedLabel = 'Copied!';
 @Component({
   selector: 'aio-code',
   template: `
-    
+
     <pre class="prettyprint lang-{{language}}">
       <button class="material-icons copy-button" (click)="doCopy()">content_copy</button>
       <code class="animated fadeIn" #codeContainer></code>
@@ -72,6 +72,8 @@ export class CodeComponent implements OnChanges {
   ngOnChanges() {
     if (!this.code) { return; }
 
+    this.code = this.code.trim();
+
     const linenums = this.getLinenums();
 
     this.setCodeHtml(this.code); // start with unformatted code