start new:
tmux
start new with session name:
tmux new -s myname
To remove a submodule you need to:
# Remove the submodule entry from .git/config
git submodule deinit -f path/to/submodule
# Remove the submodule directory from the superproject's .git/modules directory
rm -rf .git/modules/path/to/submodule
# Remove the entry in .gitmodules and remove the submodule directory located at path/to/submodule