Parse medical subject headings (MeSH) when importing PubMed text files

Thanks, I now see the issue with PMID. From what I saw, we only import the field in the XML version.

So I think the first step would be to create a small issue about adding the missing fields for PMID and the other values you think are important. I will take care of it creating one tomorrow. This makes it a suitable candidate for newcomers.

https://www.nlm.nih.gov/bsd/mms/medlineelements.html