content/experiment: fix typo

Change-Id: Ic3710a19aef5d26f28a5f873e5c6e6b57347c248
Reviewed-on: https://go-review.googlesource.com/c/blog/+/188617
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/content/experiment.article b/content/experiment.article
index a38bee2..f25726e 100644
--- a/content/experiment.article
+++ b/content/experiment.article
@@ -565,7 +565,7 @@
 Whether to make it possible to unwrap an error is an API decision,
 the same way that whether to export a struct field is an API decision.
 Sometimes it is appropriate to expose that detail to calling code,
-and sometimes you isn’t.
+and sometimes it isn’t.
 When it is, implement Unwrap.
 When it isn’t, don’t implement Unwrap.