Typo fix and Improve readability

[tmsagarofficial]

I would want to let you know that in the docs of the repo js-sdk I've found some typos and some phrases that can help the documentation be clearer and readable to the users.

Pls, assign this issue to me so that I can work on the same. Under hacktoberfest.

[ewanharris]

Thanks @tmsagarofficial! I've assigned this issue.

Just a heads up that we've merged #422 and #424 but just haven't ported them to the individual SDKs yet.

[tmsagarofficial]

Ohh ok, Thanks for the heads up @ewanharris .

[tmsagarofficial]

Check this out openfga/js-sdk#164 @ewanharris