Use Note in SyclTimer docstring

[oleksandr-pavlyk]

Use Note in dpctl.SyclTimer docstring.

Also fix grammar in the text of the note.

The change in this PR only affects docstring of dpctl.SyclTimer class.

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[github-actions]

Deleted rendered PR docs from intelpython.github.com/dpctl, latest should be updated shortly. 🤞

[coveralls]

coverage: 87.832%. remained the same
when pulling 335b9f0 on sycl-timer-use-note
into 1fac073 on master.

[github-actions]

Array API standard conformance tests for dpctl=0.17.0dev0=py310h15de555_130 ran successfully.
Passed: 906
Failed: 0
Skipped: 94

[github-actions]

Array API standard conformance tests for dpctl=0.17.0dev0=py310h15de555_131 ran successfully.
Passed: 906
Failed: 0
Skipped: 94