Documentation: Clarify pgr_kingOrdering returns reverse order

[Mohit242-bit]

Problem

The pgr_kingOrdering function documentation doesn't clarify that it returns
the reverse King ordering of an undirected graph. However, testing shows that
both pgr_cuthillMckeeOrdering and pgr_kingOrdering return identical results
on the same graph, and the Cuthill-McKee documentation explicitly mentions
"reverse order."

This inconsistency could confuse users about what the function returns.

Expectation

Update doc/ordering/pgr_kingOrdering.rst to clarify that pgr_kingOrdering
returns the reverse King ordering of an undirected graph, consistent with the
Cuthill-McKee documentation.

Files to Update

• doc/ordering/pgr_kingOrdering.rst