Identify the 0 Ohm resistor

[ChucklesOnGitHub]

We need to be explicit so ppl can easily find what they need.

Instead of "REF and GND connections tied together using a 0-ohm jumper resistor that can be removed", let's use "REF and GND connections tied together using the R1 0-ohm jumper resistor that can be removed" or whatever is appropriate in each case.

Check that the resistor label is easily visible on the device, otherwise we will need to point it out in the docs.

[ChucklesOnGitHub]

The resistor label is not easily visible in all devices. Add a section with the image and the appropriate resistor highlighted.

[ChucklesOnGitHub]

perhaps this issue is for hardware docs, but let's keep this open so we remember