content/generate: fix package statement in sample output

The input is package painkiller, not package pill.
The generated code is in the same package.

Change-Id: Ifc6dc6e5e1a035f0cec1650ab56a6f3a767fda67
GitHub-Last-Rev: 060cee29ea416effda5519874f1a3cf83a39518c
GitHub-Pull-Request: golang/blog#16
Reviewed-on: https://go-review.googlesource.com/c/143544
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/content/generate.article b/content/generate.article
index 68d7ba3..2d46713 100644
--- a/content/generate.article
+++ b/content/generate.article
@@ -152,7 +152,7 @@
 	$ cat pill_string.go
 	// generated by stringer -type Pill pill.go; DO NOT EDIT
 	
-	package pill
+	package painkiller
 	
 	import "fmt"