This expands on some of the core type descriptions, and also makes it
easier to find the documentation for each type, at least on Unix, with
a simple call like "man OSSL_ALGORITHM".
Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19842)
