Set default-terminal to tmux-256color for tmux
Set default-terminal to tmux-256color for tmux

The terminal entry for tmux-256color appears to work in my NixOS setups
now.  This enables italics within tmux and should help with
compatibility.

KibaFox/dotfiles,KibaFox/dotfiles,KibaFox/dotfiles,KibaFox/dotfiles,KibaFox/dotfiles