* Initial conversion to asciidoc

* Update and split migration guide

* Convert MIGRATION_EXAMPLES to asciidoc

* build with --focus flag

* convert migration guide to asciidoc

* cleanup migration_examples

* fix wrong Heading size

* update links in docs

* Apply suggestions from code review

Co-authored-by: Rudolf Meijering <skaapgif@gmail.com>

* Apply suggestions from code review

Co-authored-by: Rudolf Meijering <skaapgif@gmail.com>

* add tooling section

* explain purpose of each lifecycle method

* cleanup docs

* cleanup p2

* fix wrong link

* resturcture core docs

* fix wrong link

* update missing links

* Apply suggestions from code review

Co-authored-by: gchaps <33642766+gchaps@users.noreply.github.com>

* address comments

* add a commenta about plugin-helpers preconfigured

* improve density of tables

* fix lik

* remove links to the migration guide

* address comments

* Apply suggestions from code review

Co-authored-by: gchaps <33642766+gchaps@users.noreply.github.com>

* address @gchaps comments

* Apply suggestions from code review

Co-authored-by: gchaps <33642766+gchaps@users.noreply.github.com>

* change format of ES client change list

Co-authored-by: Josh Dover <me@joshdover.com>
Co-authored-by: Rudolf Meijering <skaapgif@gmail.com>
Co-authored-by: gchaps <33642766+gchaps@users.noreply.github.com>
# Conflicts:
#	docs/developer/architecture/core/saved-objects-service.asciidoc
#	docs/developer/architecture/index.asciidoc
#	src/core/MIGRATION.md
#	src/core/README.md