Sane defaults for tmux with more visible statusbar

note, May 25, 2023 on Mitja Felicijan's blog

# Remap prefix from 'C-b' to 'M-a'.
+unbind C-b
+set-option -g prefix M-a
+bind-key M-a send-prefix
+
+# Split panes using | and -.
+bind | split-window -h
+bind - split-window -v
+unbind '"'
+unbind %
+
+# Start counting windows with 1.
+set-option -g allow-rename on
+set -g base-index 1
+setw -g pane-base-index 1
+
+# Statusbar: purple bg and white fg.
+set -g status-bg '#480b8e'
+set -g status-fg '#ffffff'
+
+# Active window: black bg and white fg. 
+set -g window-status-current-format "#[fg=#ffffff]#[bg=#111111]#[fg=#ffffff]#[bg=#111111] #I:#W #[fg=#ffffff]#[bg=#111111]"
+
+# Disable mouse mode (tmux 2.1 and above).
+set -g mouse off
+