Added documentation for Otel metrics

[JonasKunz]

What does this PR do?

Adds the documentation for #2968 and #3014.

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• Start Time: 2023-03-02T08:27:48.356+0000

• Duration: 3 min 19 sec

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/test

[SylvainJuge]

LGTM, I mostly have a few suggestions for wording.

There is also a lot of "you", so I would suggest simplifying a bit to avoid duplication, also that's probably bothering me only because doing the same in French would imply that we try to be friends with the end-user, so I'm definitely biased.

[SylvainJuge]

😍

[JonasKunz]

Great suggestions, thanks!