This PR refers to the work done on setting the `Core` target as well as implemented some basic features as extension to a pair of `Swift` primitive types.
To give further details about this work:
- [x] defined the `Core` target;
- [x] implemented the **empty** static property and the **isNotEmpty()** function in the `String+Empty` extension;
- [x] implemented the **init(_: )** initialiser fo strings in the `Bool+Init` extension;
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Reviewed-on: #1
