Fix typos in README.md and Javascript samples for Azure Tables

[piraces]

Closes #11489

• As the issue states, there are some unneeded exports in the Javascript samples for Azure Tables that have been removed.
• As reported by @joheredi , the following replacements in the README.md have been done (identified as a bug): entity.PartitionKey to entity.partitionKey and entity.RowKey to entity.rowKey.
• Also a little typo in the README.md in the same section has been fixed.

[ghost]

Thank you for your contribution piraces! We will review the pull request and get back to you soon.

[joheredi]

@piraces the PR looks great! Thanks for your contribution it is much appreciated! 😄

Would you mind updating the Typescript samples to remove un-needed exports from there as well?

[piraces]

Ok I will make a commit for it too 🙂

[piraces]

@joheredi I have made a commit updating the Typescript samples to remove un-needed exports from there as well 👍

[joheredi]

Thanks a lot for your help fixing these issues, we really appreciate it!

[ghost]

Hello @joheredi!

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