Adding a new installation method to the README

[curry798]

Hello, friends in btop community.

We wrapped btop using shell and awk. Now btop users can simply x btop to quickly install and call btop in a way that does not affect the current environment.

And we record some scriptplay demos for btop: https://www.x-cmd.com/mod/btop

can the installation method provided by x-cmd be added to the btop README? I apologize in advance if it's not appropriate to raise this topic using a GitHub issue.

Looking forward to your reply :) !