MINOR: document restriction against running multiple Streams apps on same state.dir (#10187)
MINOR: document restriction against running multiple Streams apps on same state.dir (#10187)

Reviewers: Leah Thomas <0883e687a6a2021abb778c13c29c510c98a4d1e6@confluent.io>, Almog Gavra <almog@confluent.io>, Guozhang Wang <wangguoz@gmail.com>
Chasego/kafka,apache/kafka,lindong28/kafka,Chasego/kafka,lindong28/kafka,guozhangwang/kafka,guozhangwang/kafka,Chasego/kafka,apache/kafka,guozhangwang/kafka,TiVo/kafka,guozhangwang/kafka,TiVo/kafka,apache/kafka,lindong28/kafka,apache/kafka,Chasego/kafka,lindong28/kafka,TiVo/kafka,TiVo/kafka