Range continued (17): Fix formatting

Fix the formatting of `, value`. It is a code-quote and should be styled accordingly.

Change-Id: I89ac82e25c9d375e90dc01170e07c78a8e095fae
GitHub-Last-Rev: e6292b0a179f6fbf01ab5159bde517c60ba7eb94
GitHub-Pull-Request: golang/tour#488
Reviewed-on: https://go-review.googlesource.com/113998
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/content/moretypes.article b/content/moretypes.article
index 2a6138b..086a513 100644
--- a/content/moretypes.article
+++ b/content/moretypes.article
@@ -247,7 +247,7 @@
 
 You can skip the index or value by assigning to `_`.
 
-If you only want the index, drop the ", value" entirely.
+If you only want the index, drop the `, value` entirely.
 
 .play moretypes/range-continued.go