doc: documentation deprecation of process.binding

This is the first step in a long process of deprecating
`process.binding()` and replacing it with `internalBinding()`.

Eventually, once we have replaced internal uses of
`process.binding()` with `internalBinding()`, we can escalate
to a runtime deprecation and eventual end-of-life.

PR-URL: #22004
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Vladimir de Turckheim <vlad2t@hotmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Bryan English <bryan@bryanenglish.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

doc/api/deprecations.md

@@ -929,6 +929,9 @@ Type: Documentation-only (supports [`--pending-deprecation`][])
 Using `process.binding()` in general should be avoided. The type checking
 methods in particular can be replaced by using [`util.types`][].
 
+This deprecation has been superseded by the deprecation of the
+`process.binding()` API ([DEP00XX](#DEP00XX)).
+
 <a id="DEP0104"></a>
 ### DEP0104: process.env string coercion
 
@@ -987,6 +990,14 @@ Type: Documentation-only
 The option `produceCachedData` has been deprecated. Use
 [`script.createCachedData()`][] instead.
 
+<a id="DEP00XX"></a>
+### DEP00XX: process.binding()
+
+Type: Documentation-only
+
+The `process.binding()` API is intended for use by Node.js internal code
+only. Use of `process.binding()` by userland code is unsupported.
+
 [`--pending-deprecation`]: cli.html#cli_pending_deprecation
 [`Buffer.allocUnsafeSlow(size)`]: buffer.html#buffer_class_method_buffer_allocunsafeslow_size
 [`Buffer.from(array)`]: buffer.html#buffer_class_method_buffer_from_array