Document URL: https://github.com/kubevirt/must-gather/tree/b1dd8f19e65b5de47970ea2dfe0cc92955bfef64

Describe the issue:
I'm testing now the log collection from must gather command, the command I'm running is
oc adm must-gather – INSTALLATION_NAMESPACE=openshift-cnv /usr/bin/gather --vms_details
but the usage of setting the namespace – INSTALLATION_NAMESPACE doesn't written in the documentation.

Additional information:
https://github.com/kubevirt/must-gather/blob/b1dd8f19e65b5de47970ea2dfe0cc92955bfef64/collection-scripts/common.sh#LL6C31-L6C54