windows support

[PierreMacherel]

Hi,
I would like to add windows support to your project if you are OK with that.
There are multiples points to do:

• redirection like 2> /dev/null is 2>nul on windows
• bin/git_actions_preview and bin/preview_yankround_register are in bash. Bash is not on windows by default.
• fzf is able to escape some character if options are provided as array of string instead of one unique string (needed for the %).
• (optional) use cross-env to set environment variable used in package.json script
• every thing i did not think of

Item 1 & 2 may need to check the OS.
Item 3 is easy.

Let me know if you would accept one (or multiple) PR on the subject.
Thanks for your project :)

[yuki-yano]

Thanks.
I don't have Windows, but would welcome a PR as long as it doesn't break the Mac and Linux environment.