Update tmux config

It turns out that default is the color that should be used for true
transparency. Besides that, just a general clean-up of things I don't
use.

.tmux.conf

@@ -2,8 +2,6 @@
 # Copyright (C) 2018 Donovan Glover
 
 # Use the best shell
-# NOTE: zsh autocomplete does not use the correct color
-# NOTE: zsh takes longer to load compared to fish
 set -g default-shell "/bin/fish"
 
 # Offset the starting index of panes by one
@@ -47,11 +45,7 @@ bind-key l resize-pane -R 5
 bind-key v split-window -h
 bind-key s split-window -v
 
-# Switch between windows with alt+n/N
-bind -n M-N previous-window
-bind -n M-n next-window
-
-# Alternatively use shift + arrow keys to switch windows
+# Switch between windows with shift + arrow keys
 bind -n S-Left  previous-window
 bind -n S-Right next-window
 
@@ -72,8 +66,6 @@ set -g status-interval 60
 set -g status-left-length 30
 
 # Set the text for the left and right of the status line
-#set -g status-left '#[fg=blue](#S) #(whoami)#[default]'
-#set -g status-right '#[fg=blue]%H:%M#[default]'
 set -g status-left ''
 set -g status-right ''
 
@@ -81,13 +73,13 @@ set -g status-right ''
 set -g status-justify centre
 
 # Use a "transparent" background for the status line
-set -g status-bg black
+set -g status-bg default
 
 # Use the regular text color for the status line
 set -g status-fg white
 
 # Use a "transparent" background for the current window
-set -g window-status-current-bg black
+set -g window-status-current-bg default
 
 # Highlight the current window yellow and make it bold
 set -g window-status-current-fg yellow
@@ -97,7 +89,7 @@ set -g window-status-current-attr bold
 set -g renumber-windows on
 
 # Set the activity color to blue with a "transparent" background
-set-window-option -g window-status-activity-bg black
+set-window-option -g window-status-activity-bg default
 set-window-option -g window-status-activity-fg blue
 set-window-option -g window-status-activity-attr none