Merge branch '3-instructions-for-checkout-with-submodule-in-readme-file' into 'main'

Resolve "Instructions for checkout with submodule in README file"

Closes #3

See merge request !3

README.md

 # Template Kicad BE 1A Phelma - S1
 
+Check out the repository and the submodule:
+```bash
+$ git clone --recurse-submodules git@gricad-gitlab.univ-grenoble-alpes.fr:phelma/be-1a/template-kicad-be-1a-phelma-s1.git
+```