The augmented attributes are not searchable

A common issue as mentioned in the IndexAugmenter.md, the augmented attributes are not searchable. It requires the records of the augmented kind(s) to be re-indexed.

It is understandable that in order to augment the existing records, it needs to re-index the existing records of the augmented kind(s). However, there is a common scenario, data admins/managers want to verify the effect/result of the augmenter configuration immediately after they deploy the augmenter configuration. They normally don't have permission to trigger re-index. Furthermore, in this scenario, they should not trigger re-index of the whole kind(s) before they finalize the augmenter configuration for given kind(s).

If the indexer can automatically update the schema mapping of the augmented kind(s) in the ElasticSearch when it detects that the augmented configuration was updated. Then data admins/managers can see the effect/result of the augmenter configuration immediately by updating one of the existing data records or inserting a new data record. It will tremendously reduce the time on troubleshooting as well as developing and deploying new/updated augmenter configurations.

Given updating the schema mapping of the augmented kind(s) in the ElasticSearch is a lightweight operation as comparing to re-index the whole kind(s), I think it is worth to make this enhancement.