Basic authentication documentation update

Description of problem:

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

1. Follow https://github.com/openshift/console/blob/master/docs/helm/configure-namespaced-helm-repos.md for adding project helm chart repositories supporting basic auth.
2. If we create a repository and provide basicAuthConfig as shown in current documentation we will get an error.
3. The documentation here needs an update as the basicAuthConfig secret name should be specified with a `name` field

Actual results:

1. * spec.connectionConfig.basicAuthConfig: Invalid value: "string": spec.connectionConfig.basicAuthConfig in body must be of type object: "string"

   Expected results:

We should be able to add the repository supporting basic auth

Reproducibility (Always/Intermittent/Only Once):

Build Details:

Additional info:

Documentation Requirement: Yes/No (needs-docs|upstream-docs / no-doc)

Upstream: <Inputs/Requirement details>/ Not Applicable

Downstream: <Type: Doc defect/More inputs to doc>/ Not Applicable

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Release Notes Type: <New Feature/Enhancement/Known Issue/Bug
fix/Breaking change/Deprecated Functionality/Technology Preview>