Preparation for Kylin 5.0 release

1. DONE   Update frontend code 
2. WIP   Update package & install shell script
3. DONE   Update documents of new features
4. WIP   Update documents for quickstart and deployment
5. WIP   Update documents for 'upgrade from kylin 4.x'
6. WIP   Official website main page update
7. DONE   Docker image for kylin 5.0
8. DONE   Minimum configuration set for quickstart
9. WIP   Release note preparation
10. WIP   Streaming regression bug fix

Next Step

1. Finish all the 'WIP' tasks above，due date 9/14 
2. Launch the vote email of 5.0 release