doc: add note to tls docs about secureContext availability

tls.createServer() and new tls.Server() ignore secureContext option.

doc/api/tls.md

@@ -1940,8 +1940,7 @@ from `process.argv` as the default value of the `sessionIdContext` option, other
 APIs that create secure contexts have no default value.
 
 The `tls.createSecureContext()` method creates a `SecureContext` object. It is
-usable as an argument to several `tls` APIs, such as [`tls.createServer()`][]
-and [`server.addContext()`][], but has no public methods.
+usable as an argument to several `tls` APIs, such as [`server.addContext()`][], but has no public methods.  (Note: [`tls.createServer()`][] and [`tls.Server`][] constructor do *not* support the `secureContext` option.)
 
 A key is _required_ for ciphers that use certificates. Either `key` or
 `pfx` can be used to provide it.