[FEAT] Prepare ARNEIS System Integration Document

[gmacario]

Closes #280

📑 Description

✅ Checks

• [x] My pull request adheres to the code style of this project
• [ ] My code requires changes to the documentation
• [x] I have updated the documentation as required
• [x] All the tests have passed

ℹ Additional Information

[gmacario]

@alv67 ping

[gmacario]

I heard no objections so far, let's merge it as-is, if someone needs it we shall eventually improve it anyway