[DOCS-406] refer users to k8s log file collection method (#5790)
[DOCS-406] refer users to k8s log file collection method (#5790)

* add k8s note for log collection

* Update openshift/README.md

Co-Authored-By: Pierre Guceski <86850d92e00aa14eab21fd3e557d33a77ed4c5d4@datadoghq.com>

Co-authored-by: ruthnaebeck <13346691daae9c26b432144e2d404a53d02161a2@users.noreply.github.com>
Co-authored-by: Pierre Guceski <86850d92e00aa14eab21fd3e557d33a77ed4c5d4@datadoghq.com>

DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core