Sparse index return index file

[Ignalina]

https://10.101.1.9:8443/index/ ← JSON index files

You need one JSON file per crate in index///versions.json.

Cargo determines prefix from the first letters of the crate name.
Example:

aho-corasick → a/ah/aho-corasick/versions.json

example version.json

[
{
"name": "aho-corasick",
"vers": "1.1.2",
"deps": [],
"cksum": "e3b0c44298fc1c149afbf4c8996fb924...",
"features": {},
"yanked": false,
"links": null
}
]