dl: add go1.18beta1

Change-Id: Iab92b993410cbb6f11a78d52d0224ac176d0b315
Reviewed-on: https://go-review.googlesource.com/c/dl/+/371834
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: Heschi Kreinick <heschi@google.com>
diff --git a/go1.18beta1/main.go b/go1.18beta1/main.go
new file mode 100644
index 0000000..9bef121
--- /dev/null
+++ b/go1.18beta1/main.go
@@ -0,0 +1,24 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The go1.18beta1 command runs the go command from Go 1.18beta1.
+//
+// To install, run:
+//
+//     $ go install golang.org/dl/go1.18beta1@latest
+//     $ go1.18beta1 download
+//
+// And then use the go1.18beta1 command as if it were your normal go
+// command.
+//
+// See the release notes at https://tip.golang.org/doc/go1.18.
+//
+// File bugs at https://go.dev/issue/new.
+package main
+
+import "golang.org/dl/internal/version"
+
+func main() {
+	version.Run("go1.18beta1")
+}