Update projects/classes/the-shape-of-types/README.md

Author: JoshuaKGoldberg

projects/classes/the-shape-of-types/README.md

@@ -70,4 +70,4 @@ Two more exported classes must be exported that each extends `Horror`:
 
 - You may add `#` private members to the classes as you wish, such as to store previously consumed opponents.
 - Record each opponent's name, evil, and power *at the moment you consume them* — not a live reference
-- If the horror haven’t eaten yet, its power starts at 0
+- If a horror hasn't eaten yet, its power starts at 0