Docs: Additions/fixes to software block diagram
Created by: jadonk
- Don't call BeagleBone a "Linux PC" -- use something that doesn't imply an individual's desktop.
- Add cdc_acm
- Add hover text into block and make that text smaller
- Add Avahi to the diagram
- Start to define some new diagrams
- Discovery process series of diagrams
- Break down the Zephyr layers
Need additional documentation to introduce Zephyr and how we use it.