Refactored #7 out into class files like I should have to begin with.

2022/starter/Makefile

@@ -1,2 +1,2 @@
-a.out: main.cpp
-	clang++ -std=c++2b -g -O0 main.cpp
+a.out: main.cpp File.h File.cpp Folder.h Folder.cpp SplitStr.h
+	clang++ -std=c++2b -g -O0 main.cpp File.cpp Folder.cpp