Merge pull request #417 from neongreen/patch-1

Fix a typo in the spec

spec.txt

@@ -340,7 +340,7 @@ in contexts where whitespace helps to define block structure,
 tabs behave as if they were replaced by spaces with a tab stop
 of 4 characters.
 
-Thus, for exmaple, a tab can be used instead of four spaces
+Thus, for example, a tab can be used instead of four spaces
 in an indented code block.  (Note, however, that internal
 tabs are passed through as literal tabs, not expanded to
 spaces.)