Hi Effisio,
Just to add to my previous comments.
For above solution, every time you need to add a new js file/library, you will need to modify the bootstrapParams.tpl file.
But there is another solution by modifying the 'grunt' building scripts, so that you can place all your custom js libraries in one specific directory, and then during the grunt process, all the files will automatically be copied to the distribution directory and also all the required <script> tags will be added to the index.html as required.
You will just need to copy your required js libraries to a predefined path under your customization project path.
But as I said, this is by modifying the grunt scripts, and by this we are running into a problem, where by every time you upgrade your GBC, you will need to change the grunt scripts manually, so as your new changes are applied to the new GBC build.
If you are interested, please let me know, I can give you the required changes in grunt scripts.
Thanks And Regards
Susobh Sugathan