Improve API reference for `setRowOrder` and `setColumnOrder`

[sequba]

Description

API reference for setRowOrder is confusing for our users (#989 ) and should be improved.

• describe better what needs to be provided as a newRowOrder parameter
• better example - use letters as values in cells
• cross-link between setRowOrder reference and guide about sorting
• probably there is a similar issue with setColumnOrder

Links

https://github.com/handsontable/hyperformula/issues/989 https://github.com/handsontable/hyperformula/issues/947

Type of issue

• [x] Improvement to documentation