[skip ci] update readme

Update CHANGELOG.md

bump version

Merge pull request #4 from tyrchen/feature/support-column-and-constraint-rename

feature: add rename to DeltaItem trait and support rename for column/constraints of the table

fix #1. Provided benefit in readme.

Update CHANGELOG.md

fix: alter table level constraint should only drop/create that constraint. Also use ONLY for most of alter table migration.

Update CHANGELOG.md

Merge branch 'master' of github.com:tyrchen/renovate

Update CHANGELOG.md

fix: silly typo for the output of `renovate schema apply`

Update issue templates

[skip ci] improve document

[skip ci] update readme