subject(argrot1): add readme

subjects/argrot1/README.md

@@ -0,0 +1,20 @@
+## arg-rot1
+
+### Instructions
+
+Write a program that rotates the arguments in the command line by 1 position.
+- If the number of arguments is less than 2, print (`'\n'`).
+- Print (`'\n'`) at the end of the output.
+
+### Usage
+
+```console
+$ go run . | cat -e
+$
+$ go run . 1 2 3 4 5 6 7 8 9 | cat -e
+2 3 4 5 6 7 8 9 1$
+$ go run "Hello" "World" | cat -e
+World Hello$
+$ go run . a b c d
+b c d a$
+```