[DOCS] Add explicit link to create an issue

[agardnerIT]

The what's next page says "... please don't hesitate to raise an issue in this repository." and although there is a link (top right) back to this repo, it's probably more user friendly to also link from that text directly to:

https://github.com/Dynatrace/obslab-predictive-kubernetes-scaling/issues OR
https://github.com/Dynatrace/obslab-predictive-kubernetes-scaling/issues/new

Code location:

obslab-predictive-kubernetes-scaling/docs/whats-next.md

Line 17 in 3b45b22

hesitate to raise an issue in this repository.

Then git add -A && git commit -m "update" && git push && mkdocs gh-deploy to deploy new version.

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Step 7 of getting started also needs this:

obslab-predictive-kubernetes-scaling/docs/getting-started.md

Line 147 in 3b45b22

- Raise an Issue: Feel free to raise an issue in this repository for assistance.