add section about benchmarks

readme.md

@@ -37,6 +37,28 @@ May be useful in the following cases:
 
 If none of these apply, it's probably better to implement the needed operations using Javascript's Set class.
 
+### Benchmarks
+
+There's a very simple benchmark comparing the set operations difference, symmetric difference, union and intersection implemented in this library versus an implementation using Set.
+
+```
+pnpm install
+pnpm benchmark
+```
+
+Output should look something like this:
+
+```
+difference      impl: Set               size: 1000 x 39,330 ops/sec ±0.95% (94 runs sampled)
+difference      impl: ordered-sets      size: 1000 x 34,476 ops/sec ±0.27% (98 runs sampled)
+symmetric       impl: Set               size: 1000 x 80,485 ops/sec ±1.22% (93 runs sampled)
+symmetric       impl: ordered-sets      size: 1000 x 25,945 ops/sec ±0.28% (101 runs sampled)
+union           impl: Set               size: 1000 x 45,971 ops/sec ±1.13% (91 runs sampled)
+union           impl: ordered-sets      size: 1000 x 25,897 ops/sec ±0.31% (98 runs sampled)
+intersection    impl: Set               size: 1000 x 44,982 ops/sec ±0.62% (95 runs sampled)
+intersection    impl: ordered-sets      size: 1000 x 36,325 ops/sec ±0.43% (99 runs sampled)
+```
+
 ## Extension
 
 If you have a usecase for a missing feature be sure to make an issue.