Update lightning.tensor docs

[multiphaseCFD]

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---

Context:

[SC-65786] and [SC-68333]

Description of the Change:

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 56.33%. Comparing base (05ee305) to head (f52a43d).
Report is 67 commits behind head on master.

❗ There is a different number of reports uploaded between BASE (05ee305) and HEAD (f52a43d). Click for more details.

HEAD has 2 uploads less than BASE

Flag	BASE (05ee305)	HEAD (f52a43d)
	8	6

Additional details and impacted files

@@             Coverage Diff             @@
##           master     #909       +/-   ##
===========================================
- Coverage   96.27%   56.33%   -39.94%     
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  Files         214       24      -190     
  Lines       28620     2297    -26323     
===========================================
- Hits        27553     1294    -26259     
+ Misses       1067     1003       -64     

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[tomlqc]

Awesome @multiphaseCFD!
Just few suggestions about README vs device.rst

[Qottmann]

Great work @multiphaseCFD !

I am bit confused about some of the recommendations you are making, perhaps I am missing something so it would be good to clarify that to me (and to the user)

[tomlqc]

LGTM

[Qottmann]

Thanks for the update @multiphaseCFD 👍

Still some doubts and confusion around the following points:

• recommending to disable new opmath. This should be a very last resort as it will likely cause all kinds of unforseeable problems. If there are things not supported right now, we should just note that and aim at fixing that asap.
• recommending to use finite shots generally. For returning things like qml.probs and getting finite samples - sure, but for expectation values? Do we really get faster performance when using finite shots? Would be very strange if that was the case 🤔

[AmintorDusko]

Looks good!