* split tests, reorg types

and also funcion-to-module if lib,config,options detected.
Related: https://github.com/vic/den/issues/92

See:
https://github.com/vic/den/discussions/91#discussioncomment-14978857

let the functor just return a constant function

provides.itself ignores its arguments

Clarified usage of aspects system without flakes in README.

* aspect-chain contains aspect objects nor their names.

this is useful because we also have anonymous aspects
being the result of providers. even when these anonymous
aspect can be given an explicit name via `name` attribute,
it is better to pass the object itself.

* Apply suggestion from @Copilot

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

This reverts commit 66140439b9044de62dd45884b30d3f2e99f1540c.

Added badges and updated image references in README.

asp was short of aspect, but asp reminded be of dark lord micorosft

This allows providers an opportunity to inspect
the chain of aspects that caused they to be
included and can return accordingly.

also alias config as `aspects` arg in `flake.aspects` module.

Clarify the explanation of aspect functions in README.

* test aspect providers

* fix test

fix argument of providers to be just aspect and name.

Revert the change where default was removed. Now added tests to verify
flake.modules is always defined.

Fix #2.