fix: fix the eureka module's path and fix the import path in README and example

[MulL1on]

What type of PR is this?

fix: A bug fix

What this PR does / why we need it (English/Chinese):

en: fix the eureka module's path and fix the import path in README and example ch: 修改eureka module声明的路径和README和example中引入的路径

Which issue(s) this PR fixes:

https://github.com/hertz-contrib/registry/issues/81#issue-1679415993

[CLAassistant]

All committers have signed the CLA.