blog: fix formatting issue with gosumcheck code example

Change-Id: I46113112b217e12f5a739fcda1018ce035a6f7d0
Reviewed-on: https://go-review.googlesource.com/c/blog/+/192000
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/content/module-mirror-launch.article b/content/module-mirror-launch.article
index 06aff15..58b811a 100644
--- a/content/module-mirror-launch.article
+++ b/content/module-mirror-launch.article
@@ -116,7 +116,8 @@
 against the checksum database with
 [[https://godoc.org/golang.org/x/exp/sumdb/gosumcheck][gosumcheck]]:
 
-`go`get`golang.org/x/exp/sumdb/gosumcheck`gosumcheck`/path/to/go.sum`
+    go get golang.org/x/exp/sumdb/gosumcheck
+    gosumcheck /path/to/go.sum
 
 In addition to verification done by the `go` command, third-party
 auditors can hold the checksum database accountable by iterating over the log