The Business Central Community loves Git, but GitHub does not seem to even know we exist. It recognises our projects as perl projects and there is no suggestion for a .gitignore file.
It’s generally considered best practice to use Git for managing uncompiled code, but not to store the result of a project, nor it’s dependencies.
Also, settings that may vary from developer to developer are best not to be stored since doing to would continously lead to conflicts with pushing and merging.
For AL projects this means we need to exclude our .app file (the result), the alpackages (our dependencies) and the vscode settings file.
Or if you want to copy & paste
.alpackages/ .vscode/ *.app
NOTE: You should create your .gitignore before the initial commit. Removing files later is a tedious process.