[helm] very slow "helm install hwameistor/hwameistor" using online method

[alexzhc]

Using online method to do helm install hwameistor/hwameistor may take over 10 minutes (if ever successful) especially in China, because the chart URL http://hwameistor.io/helm-charts is hosted on github page. We need to offer alternative hosting for it or add acceleration to it.

Suggest adding http://helm.hwameistor.io for alternative hosting.