Update Web Worker UI Docs

Summary

This PR adds documentation on how to integrate web workers in a UI with o1js to coincide with the improvements in the reference implementation that were introduced with this PR. The documentation provides an example of how to use the comlink package introduced in the reference implementation to simplify the communication with web workers.

Closes #1047

Impact

Currently web workers are necessary to build performant and usable UIs with o1js. Integrating and managing web workers with o1js is complex, and hard to manage according to many developers on discord. These developers have requested that we simplify the process. This step by step example documentation coupled with the improved web worker reference implementation improves the DX.

Changes

Sections on worker and worker client setup was added
Instructions on how to use comlink added
Updated UI Implementation code added to documentation steps

Future Plans

The long term goal is to eliminate the need for web workers with updates to o1js. In the short term we are aiming to improve the DX of building UIs with changes like this one. The example implementation and documentation will be incrementally improved until we reach the longer term goal with improvements to o1js.

o1-labs / docs2