Please support seekable format

[joshtriplett]

There's a seekable zstd format, which makes it possible to seek to and decompress segments independently. It includes a jump table at the end for all the segments.

https://github.com/facebook/zstd/blob/dev/contrib/seekable_format/zstd_seekable_compression_format.md

I'd love to have support for this format in zstd-rs, both to compress (with an API to mark the end of a segment) and to decompress (parsing the jump table and allowing decompression of individual segments).

[NobodyXu]

There's a separate binding crate https://lib.rs/crates/zstd-seekable which can be used as a reference implementation