~/.tmux.conf: Use sakura-style keys for switching between tabs

.tmux.conf

bind-key c neww -c "#{pane_current_path}"
bind-key -n F1 select-window -t 0
bind-key -n F2 select-window -t 1
bind-key -n F3 select-window -t 2
bind-key -n F4 select-window -t 3
bind-key -n F5 select-window -t 4
bind-key -n F6 select-window -t 5
bind-key -n F7 select-window -t 6
bind-key -n F8 select-window -t 7
bind-key -n M-1 select-window -t 0
bind-key -n M-2 select-window -t 1
bind-key -n M-3 select-window -t 2
bind-key -n M-4 select-window -t 3
bind-key -n M-5 select-window -t 4
bind-key -n M-6 select-window -t 5
bind-key -n M-7 select-window -t 6
bind-key -n M-8 select-window -t 7
bind-key -n C-PageUp select-window -t:-1
bind-key -n C-PageDown select-window -t:+1