Fix broken YAML

Author: sethvargo

website/source/intro/getting-started/build.html.md

@@ -1,7 +1,7 @@
 ---
 layout: "intro"
 page_title: "Build Infrastructure"
-sidebar_current: "gettingstarted-build
+sidebar_current: "gettingstarted-build"
 description: |-
   With Terraform installed, let's dive right into it and start creating some infrastructure.
 ---