Tools for improved understanding/visibility

## Linux kernel modules

Saw this today on LinkedIn: https://github.com/kzall0c/vock

I think this would be a nice way to explore the kernel.

## Embedded serial interfaces

We should include sigrok usage as we continue through the tutorials to aid in learning about I2C/SPI/UART/PWM, etc. Nothing helps quite as much as *seeing* it in action. I'm not sure if PRU firmware can monitor all the necessary pins as-is or if there'd need to be some extra jumpering. We should consider this before we lock-in the next TechLab revision as it has stalled due to a lack of pushing it. The BeagleLogic web front-end to sigrok could be used.

See:

* https://github.com/sigrokproject/libsigrok/tree/master/src/hardware/beaglelogic
* https://github.com/abhishek-kakkar/BeagleLogic

Start by reviewing the linked vock project for Linux kernel exploration, then examine the sigrok BeagleLogic integration and the BeagleLogic project. Determine whether the existing PRU firmware can monitor the required I2C, SPI, UART, and PWM pins, including any jumper requirements. Done should mean a decided approach for incorporating visibility tools into the tutorials and the next TechLab revision.

Written by the indexing model from the issue text.