Merge pull request 'add makefile' (#1) from somali/Test:main into main

Reviewed-on: cj/Test#1

.gitignore

@@ -1 +1,2 @@
 hello
+*.o

Makefile

@@ -0,0 +1,12 @@
+ALL: hello
+
+hello.o: hello.c
+	gcc -Wall -c hello.c
+
+hello: hello.o
+	gcc -o hello hello.o
+
+clean:
+	rm -f hello.o hello
+
+.PHONY: clean