GRPA-3100: Consolidate storage configuration and convert to Butane

Convert LUKS and mirroring configuration to Butane.  Consolidate the
LUKS TPM2, LUKS Tang, and mirroring instructions into a single procedure,
since Butane needs to know about the entire storage layout at once.

Update Tang networking advice for current RHCOS features/limitations.

Document the threshold field for Shamir's Secret Sharing.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1938965

Author: bgilbert

installing/install_config/installing-customizing.adoc

@@ -28,10 +28,7 @@ ifdef::openshift-webscale[]
 include::modules/installation-special-config-rtkernel.adoc[leveloffset=+1]
 endif::openshift-webscale[]
 include::modules/installation-special-config-kmod.adoc[leveloffset=+1]
-include::modules/installation-special-config-encrypt-disk.adoc[leveloffset=+1]
-include::modules/installation-special-config-encrypt-disk-tpm2.adoc[leveloffset=+2]
-include::modules/installation-special-config-encrypt-disk-tang.adoc[leveloffset=+2]
-include::modules/installation-special-config-mirrored-disk.adoc[leveloffset=+1]
+include::modules/installation-special-config-storage.adoc[leveloffset=+1]
 include::modules/installation-special-config-chrony.adoc[leveloffset=+1]
 
 ifndef::openshift-origin[]