Clarify auto-batching behavior

[guimachiavelli]

Currently, our auto-batching section indicates which operations get batched in the following way:

Meilisearch batches operations such as document addition and deletion when they:
- Target the same index
- Are immediately consecutive

This sentence relies on users carefully noticing such as, and understanding it to mean "batched operations include but are not limited to the following operations". We should rewrite it so the idea is easier to grasp.

Source: internal slack channel (private link)