git submodule init
git submodule sync

git submodule add https://path-to-readonly/repo1.git @hard-apps/repo1
git submodule add https://path-to-readonly/repo2.git @hard-apps/repo2

add repo2 to repo1:

cd @hard-apps/repo1
npm i @hard-apps/repo2

Adding new submodule app

mkdir @hard-apps/new-app
cd @hard-apps/new-app
git init
git remote add origin <origin>
cp ../../.gitignore .

Add tsc to every package.json

"script": {
	"tsc": "tsc"
}