About the repo name reasonable

[wilsonwu]

Issue Description

For the operator of sentinel could be only one to control many kinds of resources, like dashboard, token server and so on.

So could we consider to change the repo name to: sentinel-operator, because there is not only dashboard here soon.

Describe what happened (or what feature you want)

For standard of naming.

Describe what you expected to happen

Update repo name.

[wilsonwu]

@sczyh30 please think about it, because some docker image, chart name related.