[DOCS] Add user guide for read_sql #6805

Job	Run time
integration-test-build (3.7)	4m 23s
style (3.8)	1m 22s
test-imports (ubuntu, 3.7)	2m 13s
rust-tests (ubuntu)	3m 7s
test-imports (windows, 3.7)	4m 42s
rust-tests (windows)	7m 48s
unit-tests-with-coverage (3.7, py, 7.0.0, ubuntu)	5m 25s
unit-tests-with-coverage (3.7, py, 12, ubuntu)	9m 50s
unit-tests-with-coverage (3.7, ray, 12, ubuntu)	11m 36s
unit-tests-with-coverage (3.10, py, 12, ubuntu)	7m 50s
unit-tests-with-coverage (3.10, py, 12, windows)	10m 52s
unit-tests-with-coverage (3.10, ray, 12, ubuntu)	11m 16s
unit-tests-with-coverage (3.10, ray, 12, windows)	14m 31s
integration-test-io (3.8, py)	6m 36s
integration-test-io (3.8, ray)	6m 25s
integration-test-iceberg (3.8, py)	4m 33s
integration-test-sql (3.8, py)	3m 52s
integration-test-io-credentialed	0s
integration-test-iceberg (3.8, ray)	4m 53s
integration-test-sql (3.8, ray)	4m 24s
integration-test-tpch (3.7, py)	2m 6s
integration-test-tpch (3.7, ray)	2m 15s
Publish coverage reports to CodeCov	8s
	2h 10m 7s

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