docs: remove reference to RoachNode (#9649)
docs: remove reference to RoachNode (#9649)

* docs: remove reference to RoachNode

* Update design.md

petermattis/cockroach,maxlang/cockroach,paperstreet/cockroach,glycerine/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,glycerine/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,maxlang/cockroach,glycerine/cockroach,vaibhavarora/cockroach,cockroachdb/cockroach,petermattis/cockroach,veteranlu/cockroach,glycerine/cockroach,vaibhavarora/cockroach,petermattis/cockroach,cockroachdb/cockroach,vaibhavarora/cockroach,vaibhavarora/cockroach,maxlang/cockroach,petermattis/cockroach,veteranlu/cockroach,glycerine/cockroach,petermattis/cockroach,cockroachdb/cockroach,vaibhavarora/cockroach,glycerine/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,maxlang/cockroach,paperstreet/cockroach,paperstreet/cockroach,cockroachdb/cockroach,maxlang/cockroach,petermattis/cockroach,cockroachdb/cockroach,maxlang/cockroach,veteranlu/cockroach,petermattis/cockroach,glycerine/cockroach,veteranlu/cockroach,cockroachdb/cockroach,paperstreet/cockroach,maxlang/cockroach,cockroachdb/cockroach,cockroachdb/cockroach,petermattis/cockroach,maxlang/cockroach,paperstreet/cockroach,veteranlu/cockroach,paperstreet/cockroach,glycerine/cockroach,paperstreet/cockroach,paperstreet/cockroach