Lo - Turn sputtering and bootstrap factors into ancillary files

[greglucas]

These are currently hard-coded values from the PDF document. We need to change these to be ancillary files to allow for future updates to these values.

imap_processing/imap_processing/lo/l2/lo_l2.py

Lines 1058 to 1061 in a6e8f1a

	# NOTE: From table 2 of the mapping document, for energy level 5 and 6
	sputter_correction_factor = xr.DataArray(
	[0.15, 0.01], dims=["energy"], coords={"energy": small_dataset["energy"]}
	)