Bundle helper bash functions as part of kube-tmuxp binary

Bundle these functions [https://github.com/arunvelsriram/kube-tmuxp#handy-bash-functions](https://github.com/arunvelsriram/kube-tmuxp#handy-bash-functions) as part of `kube-tmuxp` binary.

How to use [`fzf`](https://github.com/junegunn/fzf) in GoLang?

[https://junegunn.kr/2016/02/using-fzf-in-your-program](https://junegunn.kr/2016/02/using-fzf-in-your-program)