Add trace formats for device traces

[mosharaf]

Include a README in the folder with the format of both traces so that people can use their own trace or contribute new traces.

[mosharaf]

I just looked up the trace files themselves. They seem to be in binary format, which isn't ideal for adding new traces easily.

Why not keep the data in plain text format with an easy-to-understand schema?

[mosharaf]

@dywsjtu can you take a lead on this?