DOC: Request for additional, explicit information about tau parameter in the documentation

[dprotter]

Issue with current documentation:

Hi all, I've been getting acquainted with suite2p and noticed that there are frequent questions in the issues about which tau is appropriate for their sensor, etc. I also noticed that tau can interact with other parameters in unexpected ways, like affecting ROI detection by influencing the downsampling rate of the video. I think it would be appropriate to have a dedicated doc page around tau and how it influences processing and detection.

I did go and scan through both papers cited in the documentation, but I didnt find them very helpful for selecting appropriate tau values.

Idea or request for content:

1. Graphical representation of tau and its relationship with fluorescent sensor dynamics
2. graphical representation of tau how it impacts the different steps of processing
3. explicit discussion of how to select an appropriate tau OR binsize for ROI detection
4. explicit discussion of how to select an appropriate tau for spike deconvolution
5. table of starting tau values for common sensors

I know documentation isn't always a priority, so I'm happy to help out any way I can, IE if someone sends me some hand-sketched notes that I can turn into some vector graphics.