Corrects which levels that are prioritized differently
Corrects which levels that are prioritized differently

Both Serilog and Framework.Logging have a level called `Verbose` rather than `Trace`.  This corrects the README to reflect this.

For more information on how log levels are prioritized see [Serilog](https://github.com/serilog/serilog/wiki/Writing-Log-Events#log-event-levels) and [Framework.Logging](https://github.com/aspnet/Logging/wiki/Guidelines#log-levels)
serilog/serilog-extensions-logging,zmaruo/serilog-framework-logging,serilog/serilog-framework-logging,serilog/serilog-extensions-logging