Task scope: Add note about host name requirements to Prerequisites.

If there is a validation check for the host name, the "host validations" table should be updated as well. Note: This should be done only if there is an actual pre-flight validation check, not for a general bug.

Details:

Update the hostname-valid documentation to include details about a valid hostname.

A valid hostname:

• is 63 characters or less
• starts and ends with a lowercase alphanumerical character
• contains only lowercase alphanumerical characters, dashes, and periods

Documentation URL: https://docs.redhat.com/en/documentation/assisted_installer_for_openshift_container_platform/2024/html/installing_openshift_container_platform_with_the_assisted_installer/assembly_preinstallation-validations#host-validations-in-detail_preinstallation-validations