Subject documentation: examples with deprecated code may be confusing.

[mcw256]

I was going through docs to better understand rxjs, and was trying to experiment on my own but a lot of code examples in here: https://rxjs.dev/guide/subject use deprecated code.

Although, all the changes are writtien in here: https://rxjs.dev/deprecations/multicasting, but it is still a bit confusing and I don't know what should I learn and what I shouldn't