Indicates whether the current thread is the main thread.

The maximum number of workers allowed to exist at the same time. If not set, the program by default uses CPU core numbers as the limit.

In browsers, by default, the program loads the worker entry directly from GitHub, which could be slow due to poor internet connection, we can copy the entry file bundle/worker.mjs to a local path of our website and set this option to that path so that it can be loaded locally.