Also added a makefile

Makefile

@@ -0,0 +1,12 @@
+all:
+	cc command.cpp input_resolver.cpp main.cpp -lstdc++ -std=c++17 -O3 -L./ -lCalc -o calculator 
+
+libs:
+	cc -c -fPIC basecalc.cpp Operation.cpp
+	cc -shared basecalc.o Operation.o -o libCalc.so
+
+compile:
+	cc *.cpp -O3 -c
+
+debug:
+	cc *.cpp -g -std=c++17 -o calculator -lstdc++