_content/doc/articles/wiki: delete go.mod

This was added in CL 207263 to isolate these from the
main repo. That's not a concern anymore, and it's keeping
them out of the website module and therefore out of the embed.
Delete the go.mod to put them back.

Fixes golang/go#44314.

Change-Id: I36c20607d6132ad089ddae8150abe220eb90d3fd
Reviewed-on: https://go-review.googlesource.com/c/website/+/293410
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/_content/doc/articles/wiki/go.mod b/_content/doc/articles/wiki/go.mod
deleted file mode 100644
index 38153ed..0000000
--- a/_content/doc/articles/wiki/go.mod
+++ /dev/null
@@ -1,3 +0,0 @@
-module doc/articles/wiki
-
-go 1.14