Extra citations support for FLM

See the FLM README file.

Install with:

$ pip install flm-citations

Use the additional config front matter in your FLM files to enable citations with automatic citation retrieval from arXiv, DOI, etc.

---
$import:
  -  pkg:flm_citations
bibliography:
  - my-csl-bibliography.yaml
---

Then process your file as usual with flm.

The bibliography file(s) you provide (in the example above, my-csl-bibliography.yaml) should be in CSL JSON or CSL YAML format. They can easily be exported from Zotero, for example.

With the default configuration, the following citation keys are processed:

• \cite{arXiv:XXXX.YYYYY} - fetch citation information from the arXiv, and from its corresponding DOI if applicable.
• \cite{doi:XXX} - fetch citation information using its DOI
• \cite{manual:{X et al., Journal of Future Results (2034)}} - manual citation text
• \cite{bib:BibKey2023} - use a citation from any of your bibliography files specified in your document front matter.

In case citeproc chokes on certain entries fetched by DOI

Sometimes automatically generated citeproc/JSON entries fetched through various available online APIs (doi.org, crossref.org, arXiv.org, etc.) might not be fully conforming or exactly matching the structure expected by the citeproc-py citation formatting library that this project uses. If you run against such issues, you might consider installing a patched version of the library that smoothed out some issues I had in the past; you can install it with

> pip install git+https://github.com/phfaist/citeproc-py.git@pr-branch

until my upstream PR is considered.

Metadata Fetching

Thank you to arXiv and doi.org for use of their open access interoperability.