Add changelog.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.0' into 2.1
Update changelog.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.1' into 2.2
Update changelog.

Signed-off-by: crynobone <crynobone@gmail.com>