vpc sdk add docs on rate limiting

[powellquiring]

A golang app accessing lots of simultaneous vpc resources ended up with a non nil error code. When printed:

2022/06/05 07:38:44 VpcGenericOperation.Fetch, Get err:The system is currently unable to fulfill the request. Please retry. If the failure persists, contact support and provide the trace value from this error.
2022/06/05 07:38:44 VpcGenericOperation.Fetch, Get err:The system is currently unable to fulfill the request. Please retry. If the failure persists, contact support and provide the trace value from this error.

I can not find the docs for rate limiting

https://cloud.ibm.com/apidocs/vpc/latest?code=go

An example from a different service: https://cloud.ibm.com/apidocs/secrets-manager?code=go#rate-limits

slack Q/A: https://ibm-cloudplatform.slack.com/archives/C4XC6SWKG/p1654440955720799

[astha-jain]

Opened an internal issue to capture this item.