Update DataSink CRDS in README

[jpraychev]

When using DataSink and configure Dynatrace as backend system for storing metrics, OTLP endpoints of Dynatrace should be used.
Also, in the current version of the CRD, the connection field of the DataSink has only one field endpoint, while protocol and insecureSkipVerify are not there.

[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

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[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

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[mirzakopic]

@jpraychev thanks for the contribution if you sign the CLA we can merge the PR.

[jpraychev]

@mirzakopic I am not able to sing it here as the user I've contributed the change is another one. I've created #58 which is actually signed by me. I am closing this one.