Add every_nth snippet

snippets/every_nth.md

@@ -0,0 +1,17 @@
+---
+title: every_nth
+tags: list,beginner
+---
+
+Returns every nth element in a list.
+
+Use `[1::nth]` to create a new list that contains every nth element of the given list.
+
+```py
+def every_nth(lst, nth):
+  return lst[1::nth]
+```
+
+```py
+every_nth([1, 2, 3, 4, 5, 6], 2) # [ 2, 4, 6 ]
+```