Correct XML docs for DataModel Attributes

[JacobMikkelsen]

Description

This change corrects XML doc references to "local" indexes for "global" index attributes, "range" keys for "hash" key attributes, and fixes some small typos.

Motivation and Context

I'm new to DynamoDB, while exploring the available attributes in my IDE's autocomplete I noticed that the descriptions for some attributes seemed to mismatch what the attribute actually represented. This change corrects the documentation, and removes confusion for those using the SDK. I noticed a few other typos while making the change and fixed them up as well.

Testing

Since this change only touches documentation, I haven't tested very thoroughly. I need to get my home environment running with older versions of .NET, but after unloading the 3.5 and 4.5 projects I managed to run all unit tests (except 3..5 and 4.5 specific ones) successfully.

Screenshots (if appropriate)

N/A

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have read the README document
• I have added tests to cover my changes
• All new and existing tests passed

License

• I confirm that this pull request can be released under the Apache 2 license

[dscpinheiro]

Thanks for the contribution, your PR will be included in the next release of the AWS SDK for .NET.