Add slicing tag

bot/resources/tags/slicing.md

@@ -0,0 +1,24 @@
+---
+aliases: ["slice", "seqslice", "seqslicing", "sequence-slice", "sequence-slicing"]
+embed:
+    title: "Sequence slicing"
+---
+*Slicing* is a way of accessing a part of a sequence by specifying a start, stop, and step. As with normal indexing, negative numbers can be used to count backwards.
+
+**Examples**
+```py
+>>> letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g']
+>>> letters[2:]  # from element 2 to the end
+['c', 'd', 'e', 'f', 'g']
+>>> letters[:4]  # up to element 4
+['a', 'b', 'c', 'd']
+>>> letters[3:5]  # elements 3 and 4 -- the right bound is not included
+['d', 'e']
+>>> letters[2:-1:2]  # Every other element between 2 and the last
+['c', 'e']
+>>> letters[::-1]  # The whole list in reverse
+['g', 'f', 'e', 'd', 'c', 'b', 'a']
+>>> words = "Hello world!"
+>>> words[2:7]  # Strings are also sequences
+"llo w"
+```