include docs about `streaming` in the README

[ekilah]

Requirements

• [x] I have added test coverage for new or changed functionality
• [x] I have followed the repository's pull request submission guidelines
• [x] I have validated my changes against all supported platform versions

Related issues

n/a

Describe the solution you've provided

It is otherwise non-obvious to users of react-client-sdk that streaming defaults to enabled.

Describe alternatives you've considered

n/a

Additional context

n/a

[yusinto]

Thanks for your submission. The React SDK reference docs is the definitive source of truth and it's already included under Getting started. Duplicating these docs will be burdensome and so we won't be doing that.

[ekilah]

Hm, alright