Linux spawn shell windows using tmux

Start tmux session: tmux
Split the window: ^b (Ctrl + b), then type in quote " for horizontal split, or type in % for vertical split
Detach the current session: ^b, then press key d
Attach the previous session when starting tmux: tmux attach
List all sessions: ^b, then press key l


For detailed usage, see tmux tutorias:

https://danielmiessler.com/study/tmux/

https://gist.github.com/MohamedAlaa/2961058

Captions and Cross References in R Markdown File

See this great post:

https://rstudio-pubs-static.s3.amazonaws.com/98310_b44bc54001af49d98a7b891d204652e2.html