Generate release notes on website.

[liurenjie1024]

We have landed a lot of exciting features in 0.3.0 release, it would be great if we could generate release notes as in iceberg main site

[Fokko]

I'm going to remove the milestone to unblock the 0.4.0 release. I'm happy to help here. In general, I think it would be great to add more the website (getting started etc) since it is pretty empty still.

[Xuanwo]

Agreed. This is not a blocker.