fixed checkhealth issues for focus event using tmux with neovim

tmux/tmux.conf

@@ -52,6 +52,9 @@ set -g status-left-length 20
 # Reduce the escape time for Neovim
 set-option -sg escape-time 10
 
+# Enable focus event for Neovim
+set-option -g focus-events on
+
 # Terminal feature specific to Neovim
 set-option -sa terminal-overrides ',alacritty:Tc'