DOCF-6395 content model re-org - Interactions

[siobhan-unity]

Reorganised the content, created new landing pages.

[unity-cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
2 out of 3 committers have signed the CLA.

✅ siobhan-unity
✅ duckets
❌ siobhan-gibson
_{You have signed the CLA already but the status is still pending? Let us recheck it.}