[openssl/openssl] b4ac0b: Add documentation for "NULL" cipher and digest alg...

[Shane]

  Branch: refs/heads/openssl-3.1
  Home:   https://github.com/openssl/openssl
  Commit: b4ac0bfc320dc79c07ad829414aac74a50897e2e
      https://github.com/openssl/openssl/commit/b4ac0bfc320dc79c07ad829414aac74a50897e2e
  Author: slontis <shane.lontis at oracle.com>
  Date:   2023-02-28 (Tue, 28 Feb 2023)

  Changed paths:
    M doc/build.info
    A doc/man7/EVP_CIPHER-NULL.pod
    A doc/man7/EVP_MD-NULL.pod
    M doc/man7/OSSL_PROVIDER-default.pod
    M doc/man7/provider-cipher.pod
    M doc/man7/provider-digest.pod

  Log Message:
  -----------
  Add documentation for "NULL" cipher and digest algorithms.

Fixes #20340

Reviewed-by: Matt Caswell <matt at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20356)

(cherry picked from commit f7d76c3d7d09d95a9ceb5b69c8f951f53237ef78)