Add feature gix/zlib-rs

Author: NobodyXu

gix/Cargo.toml

@@ -264,6 +264,9 @@ fast-sha1 = ["gix-features/fast-sha1"]
 ## Note that this will cause duplicate symbol errors if the application also depends on `zlib` - use `zlib-ng-compat` in that case.
 zlib-ng = ["gix-features/zlib-ng"]
 
+## Use the rust-based zlib backend, which can compress and decompress significantly faster and is on par with zlib-ng or even faster.
+zlib-rs = ["gix-features/zlib-rs"]
+
 ## Use zlib-ng via its zlib-compat API. Useful if you already need zlib for C
 ## code elsewhere in your dependencies. Otherwise, use `zlib-ng`.
 zlib-ng-compat = ["gix-features/zlib-ng-compat"]