Add DaoCloud to the vendor list of OTel

[windsonsea]

DaoCloud provides a k8s-based platform, named DCE, in China past and recently exploring international market.

DCE well supports for observability with OTel.

[cartermp]

Thanks! FYI, the certification for the website is invalid - I won't treat that as a blocker to merge because it's clearly a legitimate site, but I figured you'd want to know.

[chalin]

@windsonsea - it would be great if the certificate can be updated, otherwise it causes an external link check failure:

Get "https://docs.daocloud.io/en/insight/06UserGuide/01quickstart/otel/otel/": x509: certificate has expired or is not yet valid: current time 2023-02-15T21:02:12-05:00 is after 2023-01-20T23:59:59Z --- ecosystem/vendors/index.html --> https://docs.daocloud.io/en/insight/06UserGuide/01quickstart/otel/otel/