Add troubleshooting instructions specific to Kubernetes environments

[atoulme]

What needs to be changed?
Add docs to the troubleshooting page for the collector explaining how to use kubectl debug with the collector and Kubernetes.

What is the name + path of the page that needs changed?
https://opentelemetry.io/docs/collector/troubleshooting/

Additional context:

A great tool to debug issues with the collector is to use this kubectl command and image:

kubectl debug -it <pod_name> --image nicolaka/netshoot -- /bin/bash

That image contains all the networking troubleshooting tools such as tcpdump, netstat, etc.