İnterpreter version (pre-AST implementation)

This version is the latest version before AST implementation. Normally there is nothing to share as a release, but from this point on the project will continue to be designed with AST.

In this version;

• Variable definition
• Using variables in expressions
• Handling arithmetic expressions
• Handling logical operators
  ...

some functions can be fulfilled. It should be noted that this version is an interpreter.