Add Dynatrace Query langage

[henrikrexed]

Describing the Dynatrace Query Langage and adding few examples on how to query :

• traces
• metrics

[alolita]

@manolama can you review too?

[manolama]

@alolita Done but it looks like I still don't have write access so it doesn't consider the my approval acceptable.

[alolita]

Thanks for reviewing @manolama

[manolama]

We could also squash merge to clear up the DCO check. Some are signed.

[alolita]

@henrikrexed please sign the DCO so that we can merge the PR.