update readme

README.md

@@ -86,6 +86,12 @@ To run with multiple features, make sure to double quote the features. e.g.
 RUSTFLAGS="--emit=asm -C target-feature=+bmi2,+adx" cargo +nightly test --features "asm bls12_381"
 ```
 
+To bench `algebra-benches` with greater accuracy, especially for functions with execution times on the order of nanoseconds, use the `n_fold` feature
+```bash
+cargo +nightly bench --features "n_fold bls12_381"
+```
+
+
 ## License
 
 ZEXE is licensed under either of the following licenses, at your discretion.