Update redis.adoc

[xwh1108]

Fix some errors related to automatic configuration in the Redis vector database

[dev-jonghoonpark]

related #2517

• In my PR, I kept the index-name in the documentation and modified the code related it.
  Since other modules also use index-name, I thought it would be good for consistency.

[xwh1108]

相关#2517

but spring.ai.vectorstore.redis.batching-strategy is remove

[dev-jonghoonpark]

Yes, that's right.
As I recall, there have also been cases in other vector stores where the batching-strategy doesn't actually exist. (but exist in document)

[xwh1108]

ok,I will create a new pr fix it only