create a snippet directory and move sample

wasm/notebook/snippets/python-markdown-math.txt

@@ -65,4 +65,4 @@ print("RustPython called back and said people need to have")
 import random 
 rnd = random.randint(1,5)
 
-print("nice " * rnd + "things.")
+print("nice " * rnd + "things.")