Update get_started.rst

[mrlucmorin]

-Fixed a typo for proper code markdown. -The "Custom operator" section gives an error on Python 3.10.6 (Windows 10 64 bits): TypeError: Observable.subscribe() takes from 1 to 4 positional arguments but 5 were given

Apparently, the call to "source.subscribe(...)" on line 194, requires that the "scheduler" argument be explicitly named. This would seem to fall in line with https://github.com/ReactiveX/RxPY/blob/7482616d623a6772f0cb649b67fa316e3a82b489/reactivex/observable/observable.py#L75

I'm a beginner with Python as a language, PyCharm as my IDE, and using RxPy, so I might be doing things wrong, but when I name the scheduler argument, things work as expected.

[coveralls]

Coverage remained the same at 93.375% when pulling a7572b85b05db1832ac5bfd2b38d62cbf1097300 on mrlucmorin:patch-1 into 7482616d623a6772f0cb649b67fa316e3a82b489 on ReactiveX:master.

[mrlucmorin]

What's the update schedule on readthedocs.io?

[dbrattli]

It updates on master merge, so it should already be updated. https://rxpy.readthedocs.io/en/latest/get_started.html

[mrlucmorin]

Maybe I was getting a cached page, but it's updated now.