website: tweak ambiguous nesting of punctuation inside quotes

Our prevailing writing style is to place punctuation outside of quotes, since in many contexts Terraform itself treats punctuation within quotes as significant and so it can be confusing to use punctuation in quotes in our prose.

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

@@ -90,7 +90,7 @@ This is a complete configuration that Terraform is ready to apply.
 The general structure should be intuitive and straightforward.
 
 The `provider` block is used to configure the named provider, in
-our case "aws." A provider is responsible for creating and
+our case "aws". A provider is responsible for creating and
 managing resources. Multiple provider blocks can exist if a
 Terraform configuration is composed of multiple providers,
 which is a common situation.