Suggestions for documentation

This is a great piece of software and super helpful for configuring MODFLOW models! I have a couple small suggestions for things I wasn't sure about in the configuration.

1. Most of the examples use TIF files for things like layer elevations, etc. Can we also use shapefiles? If so, is there a way to specify which attribute should be used in a shapefile? (For example, we have a shapefile with a model grid made by an initial cut at the model with mfsetup and sampled elevations to it but it has multiple attributes).
2. For time series like recharge, the examples mostly use netCDF which is great but not always available. You explained to me offline that one can provide individual files per period which obviates the need for resample_method and period_data information. I didn't find the specific example YML file that used this approach as I browsed, however, so would be good to have an explicit description
3. The nature of the source_data block could be explained a bit more explicitly. As I was hacking examples, I tried replacing files used for botm for example with single values in the source_data not understanding that source_data was only for files.

[aleaf]

Adding to this:

4. While the blocks in the YML file correspond well with the blocks for packages, I think it would be helpful to point out someplace in the docs which are the higher level blocks that are modflow-setup specific (like “setup_grid”, “intermediate_data” or “model” or “postprocessing”). Maybe having a list of those on the page https://aleaf.github.io/modflow-setup/config-file-structure.html
5. The sub-blocks are pretty well explained on the page but a comprehensive list of additional options would probably help as well.
6. The blahblahfile_fmt string option (like ‘hk_{:d}.dat’) is super cool but likely should be called out specifically?
7. Is there any control over how resampling is happening with rasterstates? Like using mean, min, or max or is it always interpolation to points?
8. For recharge is it possible to provide something like “rch_fils_{:d}.dat” with a file per stress period? That way people using ASCII already aligned properly in time could abbreviate their YML file a bit

[aleaf]

Added two sections to the documentation: one for explaining some of the broader concepts and methods, and another for detailing input by MODFLOW package type (or maybe variable). Not entirely sure yet how these fit together. Definitely don't want to have things in two places, but for some topics like OC, only the input really needs to be explained, while other topics like discretization strategies need more explanation. Would welcome any input from you (@mnfienen) @ntdosch or others.