Export LANG in ZSH

This fixes an issue with the p10k prompt theme I was using saying a
character was not in range as it uses unicode characters. This was only
happening over SSH.

romkatv/powerlevel10k#153 (comment)

Author: tylerbodway

zsh/zshenv

@@ -6,6 +6,9 @@ export HISTSIZE=1000
 export SAVEHIST=999
 export SHELL_SESSIONS_DISABLE=1
 
+export LC_ALL="en_US.UTF-8"
+export LANG="en_US.UTF-8"
+
 export EDITOR="nvim"
 export VISUAL="nvim"