MINOR: Fix left/outer join descriptions in Streams DSL reference topic (#10453)
MINOR: Fix left/outer join descriptions in Streams DSL reference topic (#10453)

Reviewer: Matthias J. Sax <e388d34fd3c0456122779e95f262c0d70198a168@confluent.io>
TiVo/kafka,lindong28/kafka,guozhangwang/kafka,TiVo/kafka,apache/kafka,apache/kafka,apache/kafka,apache/kafka,guozhangwang/kafka,guozhangwang/kafka,lindong28/kafka,TiVo/kafka,TiVo/kafka,lindong28/kafka,lindong28/kafka,guozhangwang/kafka