Merge 'sbroad' from submodule

sbroad/.cargo/config.toml

sbroad/.gitignore

sbroad/.gitlab-ci.yml

sbroad/.gitlab/merge_request_templates/default.md

sbroad/.luacheckrc

sbroad/AUTHORS

sbroad/Cargo.lock

sbroad/Cargo.toml

sbroad/LICENSE

sbroad/Makefile

sbroad/README.md

sbroad/audit.toml

sbroad/ci/Dockerfile

sbroad/ci/docker_template.stress

sbroad/ci/entrypoint-stress.sh

sbroad/deps.sh

sbroad/doc/design/global_tables_rfc.md

sbroad/doc/design/sbroad-2.pdf

sbroad/doc/design/sbroad.pdf

sbroad/doc/sql/query.ebnf