add natspec and documentation (#54) (#56)

* add natspec and documentation (#54)

* added dodoc, started rewriting README

* finished first pass on README

* updated .env.example

* move IStateReceiver to interfaces/

* added natspec to common/

* docs: add natspec for `ChildValidatorSet`

* docs: fix some natspec

* natspec for libs

* natspec on cvs for initialize

* natspec finished for root

* improving natspec, additional READMEs

* delete TODO

* fixes, recompile docs

* docs: clarify some `ChildValidatorSet` natspec

* fixes II

Co-authored-by: Zero Ekkusu <[email protected]>
Co-authored-by: gretzke <[email protected]>

* prettier

Co-authored-by: Zero Ekkusu <[email protected]>
Co-authored-by: gretzke <[email protected]>