Analyze sensor IP blocks and create outline for adding trigger/done signals

[annikaolson]

This issue is a sub-issue of #323.

Sensors to modify:

• ADC: ADC doc
  • Add support for trigger to begin conversion
  • Add a "done" signal when conversion is complete, currently no done signal as an output
• Encoder: Encoder doc, More encoder info
  • Replace the "or" in the synchronizer logic to be based on new trigger
  • Figure out how to incorporate a "done" when the sampling is done - not inherently supporting this
• Eddy current sensor
  • Done output already exists as per #304, will just need to be hooked up to the new IP core
  • Modify current trigger to be "enable" - currently, enable (which is passed into trigger) is based on PWM, but the new trigger will already be based on it - modify existing
• AMDS: AMDS documentation

Look into each IP core and understand the architecture with regards to how this can be implemented.

Goal: Understand how to add this feature for each sensor and have a general "sketch", or outline of how to add this so to create instructions for following issues.