Add references to the DevoxxBE talk, restructure the page

[oleg-nenashev]

Adopts code tabs and also adds more information. I will refactor the page later, just the content now

References

• TODO

Submitter checklist

• [ ] The PR request is well described and justified, including the body and the references
• [ ] The PR title represents the desired changelog entry
• [ ] If the change against WireMock 2 functionality (incompatible with WireMock 3), it is submitted against the 2.x branch
• [ ] The repository's code style is followed (see the contributing guide)

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