Add any plugin (#2801)

* Add any plugin

This adds the any plugin, a plain copy of coredns/any documented here
https://coredns.io/explugins/any/ as an external plugin.

Fixes: #2785

Signed-off-by: Miek Gieben <miek@miek.nl>

* Stickler bot nit

Signed-off-by: Miek Gieben <miek@miek.nl>

plugin/any/README.md

@@ -0,0 +1,36 @@
+
+# any
+
+## Name
+
+*any* - give a minimal response to ANY queries.
+
+## Description
+
+*any* basically blocks ANY queries by responding to them with a short HINFO reply. See [RFC
+8482](https://tools.ietf.org/html/rfc8482) for details.
+
+## Syntax
+
+~~~ txt
+any
+~~~
+
+## Examples
+
+~~~ corefile
+example.org {
+    whoami
+    any
+}
+~~~
+
+A `dig +nocmd ANY example.org +noall +answer` now returns:
+
+~~~ txt
+example.org.  8482	IN	HINFO	"ANY obsoleted" "See RFC 8482"
+~~~
+
+## Also See
+
+[RFC 8482](https://tools.ietf.org/html/rfc8482).