Update examples for the ? quantifier in documentation to include end-of-string matching.

Author: andy1li

stage_descriptions/base-10-ny8.md

@@ -5,9 +5,9 @@ In this stage, you'll add support for the zero or one quantifier (`?`).
 The `?` quantifier makes the preceding character or character class optional, meaning it can appear either once or not at all.
 
 For example:
+
 - `dogs?` matches `"dog"` (zero `"s"`)
 - `dogs?` matches `"dogs"` (one `"s"`)
-- `dogs?` does not match `"dogss"` (two `"s"`)
 - `dogs?` does not match `"cat"` (doesn't match `"dog"` pattern)
 - `colou?r` matches `"color"` (zero `"u"`)
 - `colou?r` matches `"colour"` (one `"u"`)