Update installation instructions for MacOS (via dedicated brew formula)

[Elastino]

Hello, Manim team, as of July/2024, Homebrew installs Manim and its dependencies.
Guideline for installing dependencies with brew, and attempt to install using pip3 will no longer work either venv or not.
Now homebrew team manages python resources as "System-wide" only with Brew installed resources.
Hence, to give first time installer just leave a single line install command would be the simplest option we have.

[JasonGrace2282]

Hello, thanks for helping clean up the docs!
I did want to ask what machine(s) have you tested this on?

[Elastino]

Hello.
If you are interested in support architecture and OS by home-brew.
Please refer to this.
Homebrew/homebrew-core@61c1976

If you are interested what I tested,
I used MacBook Air(M1 silicon) with MacOS 15 Beta, and MacBook Pro(2016, Intel silicon) with MacOS 12.7.5.
Both cases, brew successfully installed Manim with single line install request.

[behackl]

I was not aware there was a brew recipe for manim, nice -- although it also means that we should probably take care of upgrading it as part of our release checklist.

Thanks for the patch! I'll merge it for now -- but things might change until the next release, as we are more or less in the progress of rewriting our installation docs anyways.