content/static: update copy in sidebar details section

Changes "Has go.mod file" to "Valid go.mod" file.

Change-Id: Ib6820f16fb257c3e15da69d00dddfc099de75809
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/278533
Trust: Jamal Carvalho <jamal@golang.org>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
Reviewed-by: Julie Qiu <julie@golang.org>
diff --git a/content/static/html/helpers/_unit_meta.tmpl b/content/static/html/helpers/_unit_meta.tmpl
index 3944c4b..cd04dba 100644
--- a/content/static/html/helpers/_unit_meta.tmpl
+++ b/content/static/html/helpers/_unit_meta.tmpl
@@ -56,7 +56,7 @@
     <ul>
       <li>
         {{template "unit_meta_details_check" .Unit.HasGoMod}}
-        Has <a href="{{.Details.ModFileURL}}" target="_blank">go.mod</a> file
+        Valid <a href="{{.Details.ModFileURL}}" target="_blank">go.mod</a> file
         {{template "unit_meta_details_toggletip" "The Go module system was introduced in Go 1.11 and is the official dependency management solution for Go."}}
       </li>
       <li>