Provide more context for reordercap and examples of how to create an out-of-order pcap

[pocc]

Feedback from Jasper:

The "Sanitze the Packet Capture" mentions "reordercap" but doesn't explain what could cause packets to be out of order. This is one of the parts where I think you'll add more content later to explain in greater detail why someone might need to use those tools.

This covers /share/pcap_preparation/#sanitize-the-packet-capture, /edit/reordercap