VMAlert datasource bearer token isn't documented

The CRD reference in the API docs for vmalert doesn't show that bearer tokens are a possibility to use with the datasource options. VMAlert supports this option and the operator successfully applies this configuration when the fields are present in the CRD.

apiVersion: operator.victoriametrics.com/v1beta1
kind: VMAlert
metadata:
  name: vmalert
  namespace: victoria-metrics
spec:
  datasource:
    url: http://vmauth-vmalert:8427
    bearerTokenSecret:
      name: vmalert-token
      key: token

Start with the API documentation and CRD reference for VMAlert, locating the datasource options shown in the issue. Document the bearerTokenSecret name and key fields, using the provided manifest as the example, and verify the generated or rendered reference includes this supported configuration.