initial commit of a project with dependencies already having .git

I am new to the use of github. I am working locally on a Laravel project (not from homestead, but with Laragon) Now, I wanted to put it on github. I would prefer using github desktop, but if command lines are necessary, i will use them.

I made a repo in github, cloned it, and copy/pasted my project in it. when I tried to make the commit -- using github desktop -- I got the following messsage :

could not commit submodules vendor/doctrine/dbal
add them as submodule from git shell or remove their .git folder to add them as regular directories instead

the dbal folder, indeed, has a .gitattribute file.
Do I have to work this out manually ? there are many .gitattribute files from many dependencies in the Laravel framework. Thank you in advance for your answers.

via Chebli Mohamed