[Infra UI] Add documentation for known workarounds (#253)

* Documenting known workarounds

* add 6.6 specific instructions

Author: simianhacker

docs/en/infraops/installation.asciidoc

@@ -156,3 +156,8 @@ configuration]
 * {metricbeat-ref}/configuration-autodiscover.html[{metricbeat} autodiscover
 configuration]
 
+
+[float]
+==== Known Workarounds
+
+*Running Metricbeat <=6.5 with Kibana 6.6+*:: For Kubernetes, you will need to change the "Pod ID" field in the "Configure Source" panel (`xpack.infra.sources.default.fields.pod` in `config/kibana.yml` for Kibana 6.6) to `kubernetes.pod.name`. There is a caveat for this workaround; if you have two pods with the same name, only one will be visible in the UI.