feat: add PsychonautWiki

closes #45

README.md

@@ -79,6 +79,7 @@ Contributions are very welcome - please follow the [guidelines](CONTRIBUTING.md)
 - [LOTUS](https://zenodo.org/communities/the-lotus-initiative): harmonization, curation, validation and open dissemination of 750,000+ referenced structure-organism pairs (relationships between molecular structures and the living organisms from which they were identified).
 - [MetXBioDB Metabolite Biotransformations](https://zenodo.org/record/4247792#.Y_uK3NJBypN): a comprehensive collection of biotransformation reactions and metabolite information from the BioTransformer database. It includes the transformation and metabolism of metabolites.
 - [PAMPA Permeability and NCATS dataset](https://doi.org/10.1177/24725552211017520): is a dataset of commonly employed assay to evaluate drug permeability across the cellular membrane to help in ADME prediction.
+- [PsychonautWiki](https://psychonautwiki.org/wiki/Psychoactive_substance_index): catalog of mind-altering substances
 - [QSAR datasets - Meta-QSAR (phase I & II)](https://data.mendeley.com/datasets/spwgrcnjdg/1): Data (extracted from ChEMBL) used in Olier et al. Meta-QSAR: a large-scale application of meta-learning to drug design and discovery.
 - [The Human Metabolome Database (HMDB)](https://hmdb.ca/): is a freely available electronic database containing detailed information about small molecule metabolites found in the human body.
 - [The Metabolism and Transport Database ](https://www-metrabase.ch.cam.ac.uk/metrabaseui/pageview/download/): is a cheminformatics and bioinformatics resource that contains curated data related to human small molecule metabolism and transport.