Add initial batch line lists

[tepickering]

This PR adds an initial batch of line lists to use for wavelength calibration. One batch is taken directly from IRAF's noao package, the other is taken from NIST's ASD (https://www.nist.gov/pml/atomic-spectra-database-contents). The IRAF lists include both air and vacuum wavelengths. The files have been sorted accordingly into separate directories here.

[jehturner]

Great 👍. Would it be helpful to have those in a standard format? I imagine they'll get loaded into some fixed abstraction in Python, but the issue may be consistency for users who want to edit a copy (other than programatically)? Just a thought.

[tepickering]

i was originally thinking of abstract-ifying in python, but there is a good argument to be made for making them into a standard format. maybe ecsv that includes dtype and unit metadata. at any rate, wanted to at least get the raw data into the version history so we can track what we do with it.

[jehturner]

At some point I should check whether it makes sense to add our line lists for GMOS and other instruments or whether they are mostly replicating information elsewhere in IRAF. Of course we'll eventually distribute them with Gemini's Python package anyway and I suspect you just want a few authoritative sources in specreduce, not every instrument-specific thing that someone has come up with, so that's probably the answer.