Added configuration options

What's Changed

• Update configurability and docker documentation by @PGijsbers in #245
• Update dev docs with recent information on how to run tests by @PGijsbers in #240
• [MNT] Use new test database image by @PGijsbers in #236
• Bump PHP image version by @PGijsbers in #239

Full Changelog: v0.0.1-alpha...v0.0.2-alpha

v0.0.1-alpha: Add workflow to publish docker image on release (#234)

This release is not intended for non-developer use.