code review 5834043: doc: add Gobs of data article

doc/progs/gobs1.go

+// Copyright 2011 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.
+
+package gobs1
+
+type T struct{ X, Y, Z int } // Only exported fields are encoded and decoded.
+var t = T{X: 7, Y: 0, Z: 8}
+
+// STOP OMIT
+
+type U struct{ X, Y *int8 } // Note: pointers to int8s
+var u U
+
+// STOP OMIT
+
+type Node struct {
+        Value       int
+        Left, Right *Node
+}
+
+// STOP OMIT