Document that in some headstages probes have to be connected to the headstage for it to achieve lock with the system

[ChucklesOnGitHub]

Document that in some headstages (passthrough devices NP1.0e, NP2.0e? or all neuropixles hs NP1.0f, NP1.0e, NP2.0e?), the probe(s) need to be connected to the headstage for it to achieve lock with the system, because the clock is taken from the probe itself. This is relevant when users look to test the system before actual usage.

Clarify that, since dummy neuropixels probes do not have any functional electronics, they do not work for testing the system. They are mostly meant for testing mounting without worrying as much about breaking the shank.

Maybe:

• Include a section about what passthrough devices are in the hardware docs, maybe headstages section, since it used to be mentioned in the old software library documentation which has been deprecated.
• Identify each device that needs this in their individual page in the Hardware Guide