Making it easier for new users to download EFES

[severusseptimius]

Right now there are a few steps in the instalation process that can seem complicated to new users. I propose a script that downloads EFES and the stylesheets, which the user just has to execute.
For Linux/Mac:
install.sh
For Windows (must be renamed to install.bat; github doesn't support uploading of .bat file):
install.bat.txt

[IreneVagionakis]

Nice idea!
For MacOS, I'd use curl instead of wget, since the former usually comes pre-installed, whereas the latter doesn't.
install.sh