Add Fizz Buzz in Rexx (#5274)

Author: rzuckerm

archive/r/rexx/fizz-buzz.rexx

@@ -0,0 +1,10 @@
+do i = 1 to 100
+    if i // 15 == 0 then
+        say "FizzBuzz"
+    else if i // 3 == 0 then
+        say "Fizz"
+    else if i // 5 == 0 then
+        say "Buzz"
+    else
+        say i
+end