Add guidance for connection Pool

[pierrelambert]

It appears that it is not that direct/trivial to override default pool config from spring data.
Using spring.data.redis.jedis.pool.* properties is not overriding default values.

One way to solve this was to use a JedisClientConfigurationBuilderCustomizer

as described here: spring-projects/spring-boot#33814

It would be nice to have some documentation/material on the alternatives / way to do such using redis-om-spring.

[bsbodden]

@maorohana-redis can you take on this?

[pierrelambert]

any update ?