Add procedure to get SCAP contents for Enterprise Linux from RPM (#4218)

https://github.com/ComplianceAsCode/content does not provide any SCAP
contents for hosts running Rocky Linux. Instead, the Rocky Linux project
packages SCAP contents as RPM.

Refs PR #4193

(cherry picked from commit 0ab63db)

Resolved a minor merge conflict by dropping changes in
"guides/common/assembly_configuring-scap-contents.adoc". Instead, the
procedure is part of
"guides/doc-Managing_Security_Compliance/master.adoc".

Fixed a broken xref.

Author: maximiliankolb

guides/common/attributes-base.adoc

@@ -151,6 +151,7 @@
 :SmartProxy: Smart{nbsp}Proxy
 :SmartProxyServer: {SmartProxy}{nbsp}server
 :SmartProxyServers: {SmartProxyServer}s
+:ssg-file-name: ssg-rl10-ds.xml
 :ssg-version: 0.1.77
 :Team: {Project} community
 // Red Hat Insights

guides/common/modules/proc_getting-scap-contents-for-enterprise-linux.adoc

@@ -0,0 +1,36 @@
+:_mod-docs-content-type: PROCEDURE
+
+[id="getting-scap-contents-for-enterprise-linux"]
+= Getting SCAP contents for {EL}
+
+You can get the packaged SCAP Security Guide (SSG) for {EL} from its default operating system repositories.
+
+// Example is for Rocky Linux because that's the only Client OS that is not part of https://github.com/ComplianceAsCode/content
+ifndef::orcharhino[]
+This example works for Rocky Linux 10.
+For AlmaLinux 10, you have to adjust the file name.
+endif::[]
+
+.Prerequisites
+* Your host runs {EL}.
++
+Alternatively, you can perform this procedure in a container on your local machine.
+* Your host has `dnf-command(download)` and `cpio` installed.
+
+.Procedure
+. On your host running {EL}, download the packaged SCAP contents:
++
+[options="nowrap", subs="+quotes,attributes,verbatim"]
+----
+$ dnf download scap-security-guide
+----
+. Extract the SCAP contents from the RPM package:
++
+[options="nowrap", subs="+quotes,attributes,verbatim"]
+----
+$ rpm2cpio scap-security-guide* | cpio -iv --to-stdout ./usr/share/xml/scap/ssg/content/{ssg-file-name} > {ssg-file-name}
+----
++
+This example extracts SCAP contents for {EL} 10.
+. Upload the data streams to {Project}.
+For more information, see xref:uploading-additional-scap-content-using-web-ui[].

guides/doc-Managing_Security_Compliance/master.adoc

@@ -49,6 +49,8 @@ include::common/modules/proc_getting-supported-scap-contents-for-rhel.adoc[level
 
 ifndef::satellite[]
 include::common/modules/proc_getting-scap-contents-from-upstream.adoc[leveloffset=+2]
+
+include::common/modules/proc_getting-scap-contents-for-enterprise-linux.adoc[leveloffset=+2]
 endif::[]
 
 include::common/modules/proc_uploading-additional-scap-content-using-web-ui.adoc[leveloffset=+2]