Move suggestions and limitations to FAQ section

[anwai98]

@constantinpape

I will move this from the main documentation part to the FAQs. In addition, I decided on:

• Removing the note on the requirement of precomputing embeddings while using tiling (now we support doing it on-the-fly)
• Remove the known limitation of AMG (as we now support AIS for finetuned models, and we now support full volumetric segmentation)
• I wasn't sure whether to keep this in limitations, posting here in case we decide otherwise:

  Prompt bounding boxes do not provide the full functionality for tracking yet (they cannot be used for divisions or for starting new tracks). See also [this github issue](https://github.com/computational-cell-analytics/micro-sam/issues/23).

[constantinpape]

Sounds good! Feel free to merge once the tests pass.

• I wasn't sure whether to keep this in limitations, posting here in case we decide otherwise:

We can remove it; it's a technical detail and not really a limitation.