add VPA yaml and CHANGELOG.

Created by: f10atin9

add VPA yaml and CHANGELOG. update README.md, add a note about vpa. After testing, when the resource of the container is equal to vpa.minallowed, csi-qingcloudcontroller is available. And when the resources are not enough, vpa will start autoscale. Signed-off-by: f10atin9 f10atin9@kubesphere.io