capitalize "Packer"

website/source/intro/index.html.markdown

@@ -9,7 +9,7 @@ next_title: "Why Use Packer?"
 # Introduction to Packer
 
 Welcome to the world of Packer! This introduction guide will show you what
-packer is, explain why it exists, the benefits it has to offer, and how
+Packer is, explain why it exists, the benefits it has to offer, and how
 you can get started with it. If you're already familiar with Packer, the
 [documentation](/docs) provides more of a reference for all available features.