Actually parse int expression from the string

src/parsing.cpp

@@ -25,7 +25,7 @@ namespace parsing {
                 if (token.type == token::Type::LiteralInt) {
                     stream.m_position = inner.m_position;
 
-                    auto expr = new AST::IntLiteralExpression{ 5 };
+                    auto expr = new AST::IntLiteralExpression{ std::stoi(token.content) };
                     return new std::unique_ptr<AST::Expression>{ expr };
                 }
                 else {