Set version to 21.0.2

Move documentation to a new location (keycloak#1803)

CIAM-5056

Set version to 21.0.1

Set version to 21.0.0

Set version to 20.0.5

Set version to 20.0.4

Set version to 20.0.3

Set version to 20.0.2

Set version to 20.0.1

Set version to 20.0.0