Update docs with Preamplifier Offset Discovery

[jmdelahanty]

Austin told me today that although the image quality is indeed better with the pre-amplifier offset in place, suite2p appears to struggle a bit more with finding as many cells as before. I'm wondering if this can be overcome by altering the algorithms parameters. It might be worth it to try at the very least.

Either way, we should be updating the docs to say that while we get better looking images, we're not necessarily getting higher quality data. Needs further investigation for sure...

[jmdelahanty]

I'll put images here eventually from Austin's suite2p runs, but maybe something worth thinking about @mannk2

[jmdelahanty]

It should be noted that with this no longer taken care of with the pre-amplifier offset Austin has reported the vertical lines have reappeared in the data. I think it's likely there's some slightly different suite2p parameters that could find just as many cells as before, but I don't know/think we'll have time to actually investigate this too much...