Add Simulon remote access to docs

[thisac]

Context: Simulon is now accessible to users directly via RemoteEngine but this is not described anywhere in the docs, and thus should be added.

Description of the Change:

• The "Hardware" page is renamed to "Xanadu Quantum Cloud" to encompass both hardware and cloud simulators. Since running jobs on Simulon is almost identical to running on hardware, I thought this made the most sense.
• A new entry for "Cloud simulator" is added, describing how to use Simulon via the cloud.

Benefits: Users will now know that Simulon is accessible as a target for RemoteEngine.

Possible Drawbacks: None

Related GitHub Issues: None

[codecov[bot]]

Codecov Report

Merging #547 (7248879) into master (33194f6) will not change coverage. The diff coverage is n/a.

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  Hits         8212     8212           
  Misses        148      148           

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[thisac]

Thanks @josh146 and @antalszava. I've updated the text and heading you commented on. Do you think "Hardware and cloud" works better as a main heading?

it seems like introduction/circuits.rst is also written with having a remote hardware target in mind

I think this part looks fine as it is. It already mentions "remote simulators/hardware" in the "Simulating your program" section, and the other mentions of remote access mainly discusses hardware and hardware compilation, so I think it's fine not mentioning simulators there.

Let me know if you disagree. 🙂