Fix 3rd level node's binary representation in HAMT algorithm description (#5319)

Author: delimitry

Python/hamt.c

@@ -56,7 +56,7 @@ tree structure:
                      +---+ -- +----+----+----+ -- +----+
                                       |
                      +---+ -- +----+----+----+ -- +----+
-  a 3rd level node   | 0 | .. | 04 | 05 | 06 | .. | 31 |   0b01011 = 5  (3)
+  a 3rd level node   | 0 | .. | 04 | 05 | 06 | .. | 31 |   0b00101 = 5  (3)
                      +---+ -- +----+----+----+ -- +----+
                                       |
                      +---+ -- +----+----+----+----+