Update readme

v0.2.1

- Preload all database drivers

v0.2.0

- Added voxelwind support
- API changes (removed nukkit depended methods)

Readme update

v0.1.2

- Add getDefaultConnection method
- Fixed TextFormat compatibility issue

v0.1.1

- Downgraded MySQL J-Connector (5.1.39 instead of 6.0.2) due to incompatibility with Sql2o

v0.1.0

- Included updated MySQL connector and ORMLite
- Add Sql2o library

v0.0.8

 - Added getSQLiteConnection and getMySqlConnection methods

v0.0.7

 - Fix NPE for first plugin start

v0.0.6

- Small update of config operations