All instructions are good until step 5Clean your repository. It's a bad practice to edit the history of a repo. Just git rm -r the folder you just turned into a repo and then add it again as a submodule.
"At Libre Graphics Meeting 2016 in London, Julien Deswaef presented a talk exploring how Git can aid graphic designers and other artists in their daily processes, as well as pinpointing Git's shortcomings for that user community."
Git Large File Storage (LFS) replaces large files such as audio samples, videos, datasets, and graphics with text pointers inside Git, while storing the file contents on a remote server like GitHub.com or GitHub Enterprise.