Docs / nomenclature: change "bands" to "layers"

[PeterDSteinberg]

Throughout the elm and earthio repos we use the term band to refer to each of the DataArray objects within a Dataset. This only makes sense within the context of satellite data problems. We should change the term band to channel throughout the:

• [ ] elm docs
• [ ] earthio docs (which are not yet developed and included as part of elm docs now)
• [ ] elm example notebooks / scripts
• [ ] elm code
• [ ] earthio code

[PeterDSteinberg]

After thinking about this idea more, I am wondering whether channel is the right way to go. We came up with this idea (band rename to channel) in a GIS planning meeting a month or so ago. My thought now is that we may want to go with a more neutral name like array_name. channel is part of the conda-related documentation, and has some relation in my mind to a channel for data access like a channel on TV. It could be confusing later as Earthio data catalogue ideas are built out, but I don't know what that conflict might be specifically. Is array_name better than channel or is there a different domain-independent term we should consider? cc @gbrener @jbednar @philippjfr

[jbednar]

Layer?

[PeterDSteinberg]

Layer works for me - makes sense in visualization contexts and is consistent with the GIS world. Changing the title of the issue now to save time on discussion. I'll add the deferred label to this issue. I think it will be best addressed after the file moves related to earthio and the ML refactor to take advantage of dask-searchcv and dask-glm.