Pulser Docs Revamp

[HGSilveri]

• [ ] Improve the "Quickstart" tutorial
• [ ] Clarify how to choose a device and create a register for different applications
• [ ] Make a tutorial with the whole pipeline specifically for executing a sequence on a remote QPU
• [ ] Remove parts of (or entire) tutorials that are not relevant anymore
• [ ] Add new noise types to the tutorials
• [ ] Review API reference docs, fix typos and formatting bugs and make sure all public interfaces are properly documented
• [ ] Highlight the new backend features (qpu_like, prefer_default_noise_model,...)
• [ ] Write a tutorial on arbitrary phase modulation (after #688 is merged)

[a-corni]

I would also add:

• [ ] Refresh application notebooks: Antiferro, 2-qubit gates, ...
• [ ] Add new application notebooks