Hi ONDERSAHIN,
I've been working on a package that does exactly this. It's still under development but it does the job. https://packagist.org/packages/neilherbertuk/laravel-modules - I've been working on this for a number of months and was getting fed up with copying it to new projects so thought I would release it, even if it's only to make my life easier! There are a few tutorials and packages out there that do this, but I hope to include lots of extra features such as artisan commands to help quickly create a new module. So far it can create routes and controllers. Everything else currently has to be manually made.
Even if you don't use my package, take a look at the ModuleServiceProvider.php file as that is what loads everything. On boot it looks at each folder within app/Modules and looks through it to see what it needs to load.
Neil