[OSDOCS-14938]: Adding HCP release notes to additional release notes page

Author: lahinson

release_notes/addtl-release-notes.adoc

@@ -39,6 +39,9 @@ xref:../networking/networking_operators/external_dns_operator/external-dns-opera
 F::
 xref:../security/file_integrity_operator/file-integrity-operator-release-notes.adoc#file-integrity-operator-release-notes-v0[File Integrity Operator]
 
+H::
+xref:../hosted_control_planes/hosted-control-planes-release-notes.adoc#hosted-control-planes-release-notes[{hcp-capital}]
+
 K::
 xref:../nodes/scheduling/descheduler/nodes-descheduler-release-notes.adoc#nodes-descheduler-release-notes[{descheduler-operator}]