Mention algorithms in crate description

[frewsxcv]

I was about to write a BWT crate because I could not find any existing implementations on crates.io, but google pointed me here, so it might be nice to mention the algorithms in this library in the description in the Cargo.toml file

[kvark]

👍 BWT here has evolved quite a bit due to the need to provide a rich context for further compression (in dark). I haven't found a good way to make the complexity flexible (yet).