[BUG] https://github.com/awsdocs/aws-doc-sdk-examples/blob/main/javascriptv3/example_code/dynamodb/src/ddb_getitem.js#L13

**What is the issue?**

The annotations don't match the code. `KEY_NAME_VALUE` doesn't exist in the code. Also there's no discussion of what to do with the `N` key, should that be changed or left as `N`? 
