Windows installer: option to add condabin in PATH

[paugier]

On Windows, it is not safe to add the main Miniforge script directory in PATH. However, the directory C:\Users\myusername\miniforge3\condabin should really be in PATH. There should be an option of the Windows installer to add it (and I even tend to think it should be enabled by default).

Without condabin in PATH, a workaround is to use Miniforge Prompt, but it is quite bad since in 2024 Windows users can and should use a better shell (PowerShell or Bash for example) and a better terminal (Windows Terminal for example).

The current solution is to add C:\Users\myusername\miniforge3\condabin manually in PATH (mentioned in https://github.com/conda-forge/miniforge?tab=readme-ov-file#usage), but it's not so simple for many Windows users.

[hmaarrfk]

Closing as duplicate of #453

also see #599 for why things move slow on windows.

I see you are helping answer a few questions. thank you!