Fixed the code example in README.md for publishing a start message.

[rahibbutt]

Fixes #

Proposed Changes

• Import uuid NodeJS library
• Syntax error: const zbc = new ZB.ZBClient('localhost:26500')

[jwulf]

Thanks for this PR @rahibbutt. This library is now deprecated. The new SDK is here: https://github.com/camunda/camunda-8-js-sdk