Description of problem:

4.12: https://docs.openshift.com/container-platform/4.12/updating/updating-restricted-network-cluster/mirroring-image-repository.html#oc-mirror-differential-updates_mirroring-ocp-image-repository

4.13: https://docs.openshift.com/container-platform/4.13/updating/updating-restricted-network-cluster/mirroring-image-repository.html#oc-mirror-differential-updates_mirroring-ocp-image-repository

4.14: https://docs.openshift.com/container-platform/4.14/updating/updating_a_cluster/updating_disconnected_cluster/mirroring-image-repository.html#oc-mirror-differential-updates_mirroring-ocp-image-repository

4.15: https://docs.openshift.com/container-platform/4.15/updating/updating_a_cluster/updating_disconnected_cluster/mirroring-image-repository.html#oc-mirror-differential-updates_mirroring-ocp-image-repository

fix the error in modules/oc-mirror-differential-updates.adoc is fine

completed the inital mirror

inital should be initial

Version-Release number of selected component (if applicable):

4.12+

How reproducible:

always

Steps to Reproduce:

1. see the description

Actual results:

typo for inital

Expected results:

should be initial