Wrong paper for citation

Here: [extractor_flow_documentation](https://github.com/scilus/extractor_flow_documentation/tree/main)/[source](https://github.com/scilus/extractor_flow_documentation/tree/main/source)/[reference](https://github.com/scilus/extractor_flow_documentation/tree/main/source/reference)
/references.rst

The name of the paper is wrong: this is the Tractoflow paper, not extractorflow.