adding better ref structure

_ref/KEY_GUIDE.adoc

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+= OpenSSH Key Structure Guide
+brent saner <bts@square-r00t.net>, https://r00t2.io
+Last updated {localdatetime}
+:doctype: book
+:docinfo: shared
+:data-uri:
+:imagesdir: images
+:sectlinks:
+:sectnums:
+:sectnumlevels: 7
+:toc: preamble
+:toc2: left
+:idprefix:
+:toclevels: 7
+:source-highlighter: rouge
+
+== Purpose
+This document attempts to present a much more detailed, thorough, and easily-understood form of the key formats used by OpenSSH. The extent of those formats' canonical documentation is https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key[the OpenSSH source tree's `PROTOCOL.key`^], which is a little lacking.
+
+== Basic Introduction
+=== Legacy
+==== Private Keys
+
+In OpenSSH pre-7.8, private keys are stored in their respective PEM encodingfootnote:[https://datatracker.ietf.org/doc/html/rfc7468] with no modification. These legacy private keys should be entirely usable by OpenSSL/LibreSSL/GnuTLS etc. natively with no conversion necessary.
+
+==== Public Keys
+
+Each public key *file* (`*.pub`) is written out in the following format:
+
+    A B C
+
+Where:
+
+A:: The key type (e.g. `ssh-rsa`, `ssh-ed25519`, etc.)
+B:: The public key itself, Base64footnote:[https://datatracker.ietf.org/doc/html/rfc4648]-encoded
+C:: The key's comment
+
+The structures specified in the breakdowns later in this document describe the _decoded_ version of *B* *_only_*.
+
+
+=== New "v1" Format
+==== Private Keys
+==== Public Keys
+
+== Keytype-Specific Breakdowns
+include::rsa/main.adoc[]
+
+=== ED25519