Let's git a bit init file. Use it by executing it from the raw Gist: bash <(curl -fsSL https://gist.githubusercontent.com/tiborsimon/f02970b14d497029126381f630870889/raw)

init.sh

#!/usr/bin/env bash

header () {
  local YELLOW=$(tput setaf 3)
  local BOLD=$(tput bold)
  local RESET=$(tput sgr0)
  printf "\n${YELLOW}${BOLD}== $1 ==${RESET}\n"
}

log () {
  local YELLOW=$(tput setaf 3)
  local BOLD=$(tput bold)
  local RESET=$(tput sgr0)
  printf "${YELLOW}-> $1${RESET}\n"
}

find . | grep -v "init.sh" | xargs rm -rf 1>/dev/null 2>&1

header "CREATING EMPTY REMOTE"
mkdir -p remote/super remote/sub-a remote/sub-b
cd remote/super && git init --bare && cd ../..
cd remote/sub-a && git init --bare && cd ../..
cd remote/sub-b && git init --bare && cd ../..

header "INITIALIZING SUB-A.."
log "Cloning sub-a.."
git clone remote/sub-a
cd sub-a
log "Creating initial commit.."
echo "# Sub module A" > README.md
git add --all
git commit -m "Initial commit."
log "Pushing initial commit.."
git push -u origin master
cd ..

header "INITIALIZING SUB-B.."
log "Cloning sub-b.."
git clone remote/sub-b
cd sub-b
log "Creating initial commit.."
echo "# Sub module B" > README.md
git add --all
git commit -m "Initial commit."
log "Pushing initial commit.."
git push -u origin master
cd ..

header "INITIALIZING SUPER.."
log "Cloning super.."
git clone remote/super
cd super
log "Creating initial commit.."
echo "# Super" > README.md
git add --all
git commit -m "Initial commit."
log "Adding submodules.."
git submodule add ../sub-a
git submodule add ../sub-b
git commit -m "Submodules added."
log "Pushing changes.."
git push -u origin master
cd ..

header "REPO INITIALIZATION FINISHED!"
log "Removing local repositories.."
rm -rf super sub-a sub-b