Add PARIX and ARIS indices

[PMassicotte]

https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6703ed1712ff75c3a1b74141/original/a-global-fluorescence-index-for-predicting-dissolved-organic-carbon-abundance-and-aromaticity.pdf

@MatthiasPucher

[PMassicotte]

https://github.com/PMassicotte/eemR/blob/main/R/eem_metrics.R