doc: fix typo in comment.md

Removed duplicated "package json" string.

Change-Id: Iafd2efadd420d05497d95b4ada4fcae78a1ddae8
GitHub-Last-Rev: dd0b34ef36a69fff92207a0e7bbb2e5943696ab3
GitHub-Pull-Request: golang/website#172
Reviewed-on: https://go-review.googlesource.com/c/website/+/421034
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
diff --git a/_content/doc/comment.md b/_content/doc/comment.md
index 5c1ad6e..09aae14 100644
--- a/_content/doc/comment.md
+++ b/_content/doc/comment.md
@@ -573,7 +573,7 @@
 	// “[JSON and Go].”
 	//
 	// [RFC 7159]: https://tools.ietf.org/html/rfc7159
-	// [JSON and Go]: https://golang.org/doc/articles/json_and_go.htmlpackage json
+	// [JSON and Go]: https://golang.org/doc/articles/json_and_go.html
 	package json
 
 By keeping URLs in a separate section,