Change tabulation in Makefile

examples/compilationWithMakefile/Makefile

-FC=gfortran # set Fortran compiler
-EXEC=my_exec # set executable name
-FFLAGS= # Fortran flags
+FC=gfortran  # Fortran compiler
+EXEC=my_exec # Executable name
+FFLAGS=      # Fortran compilation flags
+
+.PHONY: clean, mrproper
 
 all: $(EXEC)
 
 my_exec: saxpy.o main.o
-		$(FC) -o $(EXEC) saxpy.o main.o
+	$(FC) -o $(EXEC) saxpy.o main.o
 
 saxpy.o: saxpy.F90
-		$(FC) -c saxpy.F90
+	$(FC) -c saxpy.F90
 
 main.o: main.F90
-		$(FC) -c main.F90
+	$(FC) -c main.F90
 
 clean:
 	 rm -f *.o *~ *.mod
 
 mrproper: clean
-		rm -f $(EXEC)
+	rm -f $(EXEC)