Update config documentation

**Description**
Currently store lacks proper compression support.

**Proposed solution**
Add configurable compression with sensible defaults.

**Priority**: Low/Medium

Start by locating the configuration handling and the store implementation, since the issue does not name specific files or tests. Determine where compression belongs, define the configurable option and sensible defaults, then verify that stored data is compressed as intended and that existing configuration continues to work.

Written by the indexing model from the issue text.