insertRows shifts existing rows down and writes new records atomically.
Example
Inputs
spreadsheet, source, one-based rowNumber, and one or more header-keyed
rows are required. Record and inputMode behavior match Append rows.
The position must be in the source body or immediately after its current end.
account optionally selects the Google account binding.
Output
Returns{ affectedCells, rowNumbers, updatedRange }. rowNumbers contains
the consecutive new rows. Formatting is inherited from the previous body row
when inserting below the first body row.