Use SPI.transfer(wbuf,rbuf,count) also for read #145
  Add this suggestion to a batch that can be applied as a single commit.
  This suggestion is invalid because no changes were made to the code.
  Suggestions cannot be applied while the pull request is closed.
  Suggestions cannot be applied while viewing a subset of changes.
  Only one suggestion per line can be applied in a batch.
  Add this suggestion to a batch that can be applied as a single commit.
  Applying suggestions on deleted lines is not supported.
  You must change the existing code in this line in order to create a valid suggestion.
  Outdated suggestions cannot be applied.
  This suggestion has been applied or marked resolved.
  Suggestions cannot be applied from pending reviews.
  Suggestions cannot be applied on multi-line comments.
  Suggestions cannot be applied while the pull request is queued to merge.
  Suggestion cannot be applied right now. Please check back later.
  
    
  
    
While doing performance tests, I noticed that the special SPI.transfer(writebuf,readbuf,count) is only called for write, but not for read.
As this massively speeds up data throughput on supported MCUs, please accept this PR.
Here:
Optimized performance on LGT8F-MCUs (Nano/Atmega328p replacement), up to 14.1Mbit/s receive and 10.7Mbit/s send.
https://github.com/dbuezas/lgt8fx/wiki/Libraries-support