Feature/thermistor api

[finger563]

Description

• Added get_resistance() API which reads the voltage from the thermistor and calculates the resistance, returning it in ohms.
• Updated example to use the new api and to use ntc config for a real ntc on a real board.
• Updated and rebuilt docs.

Motivation and Context

Exposing resistance allows developers additional tools for logging and debugging (or other calculations) than what is provided by simply outputting the temperature.

How has this been tested?

Building and running the new example on a board with an NTC.

Screenshots (if appropriate, e.g. schematic, board, console logs, lab pictures):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Hardware (schematic, board, system design) change
• Software change

Checklist:

• My change requires a change to the documentation.
• I have added / updated the documentation related to this change via either README or WIKI

Software

• I have added tests to cover my changes.
• I have updated the .github/workflows/build.yml file to add my new test to the automated cloud build github action.
• All new and existing tests passed.
• My code follows the code style of this project.

Hardware

• I have updated the design files (schematic, board, libraries).
• I have attached the PDFs of the SCH / BRD to this PR
• I have updated the design output (GERBER, BOM) files.