Documentation for link Bell pair performance measurement

[rdviii]

Things to include in documentation for the link measurement:

• How to find and plot the data from the OMNeT++ GUI, and a link to the OMNeT++ documentation on this.
• A screenshot of the plot zoomed out and one zoomed in. Label the points on the screenshot so that people can learn what they mean.
• Link to OMNeT++ documentation that shows how to turn the logging on & off.
• Info on where to find the .vec output file.
• Show the format of a record in the .vec file and explain what the fields are, so that if someone wants to process the file themselves, they can.

Cases to test:

• high success probability
• medium success probability (~1 successful Bell pair per RTT)
• low success probability (~0.01 to ~0.1 successful Bell pairs per RTT)