Update quick install instructions

[jo-so]

Please update the install-instructions at https://www.smarty.net/quick_install. They use Smarty-3.0 which isn't comparable to smarty-5.4. In 5.4.3 the libs directory only contain smarty-5.4.3/libs/Smarty.class.php which doesn't match the directory structure shown in the install-instructions.

[wisskid]

The smarty dot net website is maintained by @mohrt . Up to date documentation can be found at https://smarty-php.github.io/smarty/, installation instructions for v5 at https://smarty-php.github.io/smarty/5.x/getting-started/

[jo-so]

Oh, okay. I didn't know about the difference. If @mohrt not wants to keep this as a reminder, feel free to close it.