* Add central API configuration DSL `api do ... end`
* Use this for `default_page_size` and `max_page_size`
* Make our router cabaple of describing its routes in `mix phx.routes` Chris McCord says that we could probably power that, seeing as phoenix controls both APIs, and that capability could be added to `Plug.Router`
* Finish the serializer
* Make primary key type configurable
* Make a DSL for join tables to support complex validation/hooks into how they work, support more than just table names in `join_through`
* all actions need to be performed in a transaction
* document authorization thoroughly. *batch* (default) checks need to return a list of `ids` for which the check passed.
* So many parts of the system are reliant on things having an `id` key explicitly. THis will need to be addressed some day, and will be a huge pain in the ass
*`params` should be solidified. Perhaps as a struct. Or perhaps just renamed to `action_params` where it is used.
* Since actions contain rules now, consider making it possible to list each action as its own `do` block, with an internal DSL for configuring the action. (overkill?)
* Validate rules at creation
* Maybe fix the crappy parts of optimal and bring it in for opts validation?
* The ecto internals that live on structs are going to cause problems w/ pluggability of backends, like the `%Ecto.Association.NotLoaded{}`. That backend may need to scrub the ecto specifics off of those structs.
* Make `Ash.Type` that is a superset of things like `Ecto.Type`. If we bring in ecto database-less(looking like more and more of a good idea to me) that kind of thing gets easier and we can potentially lean on ecto for type validations well.
* use a process to hold constructed DSL state, and then coalesce it all at the end. This can clean things up, and also allow us to potentially eliminate the registry. This will probably go hand in hand w/ the "capabilities" layer, where the DSL confirms that your data layer is capable of performing everything that your DSL declares