Convert draft Hardening Guide to asciidoc.

Added two new parts. Not sure if required yet.

Complete asciidoc conversion of v3 Hardening Guide

https://issues.redhat.com/browse/AAP-43908

Author: ianf77

downstream/modules/aap-hardening/con-credential-management-planning.adoc

@@ -7,7 +7,15 @@
 
 [role="_abstract"]
 
-{PlatformName} uses credentials to authenticate requests to jobs against machines, synchronize with inventory sources, and import project content from a version control system. {ControllerNameStart} manages three sets of secrets:
+{PlatformName} uses credentials to authenticate requests to jobs against machines, synchronize with inventory sources, and import project content from a version control system. 
+
+[IMPORTANT]
+====
+In the context of {ControllerName} and {EDAcontroller}, you can use both `extra_vars` and credentials to store a variety of information. 
+However, credentials are the preferred method of storing sensitive information such as passwords or API keys because they offer better security and centralized management, whereas `extra_vars` are more suitable for passing dynamic, non-sensitive data.
+====
+
+{ControllerNameStart} manages three sets of secrets:
 
 * User passwords for *local {PlatformNameShort} users*. 
 //See the xref:con-user-authentication-planning_{context}[User Authentication Planning] section of this guide for additional details.

downstream/titles/aap-hardening/master.adoc

@@ -18,3 +18,4 @@ include::aap-hardening/assembly-intro-to-aap-hardening.adoc[leveloffset=+1]
 include::aap-hardening/assembly-hardening-aap.adoc[leveloffset=+1]
 //include::aap-hardening/assembly-aap-compliance.adoc[leveloffset=+1]
 include::aap-hardening/assembly-aap-security-use-cases.adoc[leveloffset=+1]
+include::platform/assembly-eda-for-security-related-events.adoc[leveloffset=+1]