Change the type of the repository to template

[Jpfonseca]

I believe it would be better if the repository would be changed to a Template Repository. This would allow for a better tracking of the changes in different forks might be related with bugs.
As an example of this behaviour you can look to this repo.

[Jpfonseca]

Moreover I decided to add the project to the Overleaf templates for better usage. I uploaded the latest version of the code just hours ago and sumbmitted the application for the template to be available in the Overleaf Gallery with the license of the project. Link here