bamtofastq depends on bxindex, which is part of Long Ranger

[slowkow]

I ran bamtofastq --bx-list=mylist.txt my.bam and got this error message:

bamtofastq/src/bx_index.rs

Line 29 in f914d80

format!("Couldn't find BX index: '{:?}'. You must sort your BAM file with 'samtools sort -t BX' and index with 'bxindex'", bxi_fn)

I was scratching my head wondering "What is bxindex?" and searching Google without finding any results.

Then I found:
https://github.com/10XGenomics/longranger/blob/master/bin/bxindex

Now I understand that there is another project called Long Ranger that includes a Python library called tenkit that includes functions for creating a .bam.bxi file.

Would you consider including links to such dependencies for bamtofastq in the README file?

Also, I wonder if you might consider changing the error message about sorting and indexing? It could be more helpful if it included a link to the Long Ranger project, so folks can eventually figure out how to index their BAM files the way bamtofastq wants them.