I do it this way
In my .gitconfig
# Pull all repos
pullall = !git pull && git pullsub
pullsub = submodule foreach --recursive git pull
# Fetch all repos
fetchall = !git fetch --all && git fetchsub
fetchsub = submodule foreach --recursive git fetch --all
In /home/<>/.config/sublime-merge/Packages/User/ Default.sublime-commands
[
{
"caption": "pullall - pull repo and submodules",
"command": "git",
"args": {"argv": ["pullall"]}
},
{
"caption": "fetchall - fetch --all repo and submodules",
"command": "git",
"args": {"argv": ["fetchall"]}
}
]