add word path game

HOMEWORK_IDEAS.md

@@ -1,2 +1,25 @@
 * The Drunken Bishop - Draw an image based on a hash
 * Boggle(TM)d Keyboard - given a key sequence, find matching words based on fat-fingering a qwerty keyboard
+
+Word Map
+--------
+
+Find the shortest path between to words, changing only one letter at a time,
+but must match another real word with each change.
+
+Example:
+
+```
+rake -> moon
+```
+
+```
+        r         k      a         e      l        d
+rake -> make -> male -> mole -> mold -> mood -> moon
+m         l      o         d      o        n
+```
+
+Inputs:
+  * Word list (dictionary)
+  * A start word
+  * An end word