Introduce docs website (cosmos#759)

* init docusaurus repo

* unify theme with cosmos-sdk docs

* update config

* add FAQ sections

* terms

* Create overview.md

* consumer dev folder

* smol

* Create technical-specification.md

* add new stuff

* add key assignment documentation

* fix typo

* add clarification

* update documentation; add features section; improve overview

* mv website to docs root; mv old readmes to old_docs

* add doc deployer

* make deployable to github pages

* add consumer initiated slashing doc page

* sovereign -> standalone

* add validators section

* fix typos

* update small things

* rename validator stuff

* add joining-testnet docs

* add title to joining testnet

* minor refactors

* refactor faq, update testnet guide

* update footers

* update testnet repo links

* Fix typo

Change ". Ie." to ", i.e."

* Fix typo: you key => your key

* Fix typo: cosumer => consumer

* update copyright section so docusaurus builds

* Add . at the end of info boxes

* Minor grammar change

* Add missing word "the"

* Fix typo

* update broken link for ics-testnets

* Remove duplicated paragraphs

* Adjust wording

---------

Co-authored-by: Matija Salopek <[email protected]>
Co-authored-by: MSalopek <[email protected]>
Co-authored-by: Philip Offtermatt <[email protected]>

Makefile

@@ -183,3 +183,11 @@ proto-update-deps:
 
 .PHONY: proto-all proto-gen proto-gen-any proto-swagger-gen proto-format proto-lint proto-check-breaking proto-update-deps mocks
 
+###############################################################################
+###                              Documentation                              ###
+###############################################################################
+
+build-docs:
+	@cd docs && ./build.sh
+
+.PHONY: build-docs