Dtools.datastructures

* renamed class FTuple -> ftuple
* ftuple now takes 0 or 1 iterables, like list and tuple do
* created factory function for original constructor use case
* FT[D](*ds: D) -> ftuple[D]

* removed docs from repo
* docs for all grscheller namespace projects maintained here
* https://grscheller.github.io/grscheller-pypi-namespace-docs/

* Major refactoring of SplitEnd class
* splitends is now a subpackage containing the se module
* removed supporting classes
* can now be empty
* grscheller.datastructures no longer uses nada as a sentinel value
* replaced with grscheller.fp.nothingness.noValue
* made classes in nodes module less passive with better encapsulation
* compatible with:
* grscheller.fp >= 1.0.0 < 1.01
* grscheller.circular-array >= 3.6.1 < 3.7

* Does not work with either
* grscheller.fp 0.3.3 (version working for 0.21.0 release)
* grscheller.fp 0.4.0 (latest version of fp)
* Needs an upgrade
* TODO: replace Nada with MB as was done for grscheller.fp.iterables

* renamed module `split_ends` -> `stacks`

* got back to a state maintainer is happy with
* many dependencies needed updating first