docs: update query example

[hoorayimhelping]

Proposed Changes

While using the JS client in our firstMile work, I copied the code from the example and kept running into syntax errors. After I changed to the code to look the way this updated example looks, it started working properly.

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• yarn test completes successfully
• Commit messages are in semantic format

[sranka]

Thank you @hoorayimhelping for posting an issue. The only difference in the proposed change is the meaning of this in the callbacks. The meaning of this is a kind of JS pain that the programmers need not be aware of when they stick to arrow functions. So this PR sounds like a reasonable enhancement. I will update all the examples so that they are better for copy-pasting.