docs: add tested platforms

[linrongbin16]

I run a very simple demo in below platforms (so only very limited API such as execute!, Print, cursor, EnterAlternateScreen, terminal::size is been used):

1. macOS Sonama 14.4, Apple M1 Max, Silicon Chip.
2. Windows 11 Enterprise 22H2, arm64, a virtual machine running in the macOS (above) with Parallel.
3. Windows 10, x86_64, with Windows Terminal (is that a Console Host?)
4. Ubuntu 23.04, x86_64 Desktop, a virtual machine running in the Windows 10 x86_64 (above) with VMWare Workstation.

Note: the checked ones are been manually tested.

Here's the demo source code: https://github.com/rsvim/rsvim/tree/chore-demo

Here's the screen recording:

rsvim-demo.mov

[joshka]

This is a simple doc update to state that several systems are tested. It seems reasonable to merge this.