Auto merge of #11880 - ehuss:registries-doc-git, r=weihanglo

doc: Fix registries.name.index for sparse

A very minor documentation update. `registries.name.index` doesn't have to be a git URL, it can also be a sparse one.

Author: bors

src/doc/src/reference/config.md

@@ -918,7 +918,7 @@ consists of a sub-table for each named registry.
 * Default: none
 * Environment: `CARGO_REGISTRIES_<name>_INDEX`
 
-Specifies the URL of the git index for the registry.
+Specifies the URL of the index for the registry.
 
 ##### `registries.<name>.token`
 * Type: string