wrong dependency in readme

[Musimo]

fix a typo in the dependencies for Gradle and Maven in "README.md"

Gradle:
implementation 'com.edgedb:edgedb:0.2.1'

Should be changed to:
implementation 'com.edgedb:driver:0.2.1'

Maven:
artifactId: edgedb

Should be changed to:
artifactId: driver