Add benchmarks to the README.

REAME.md

@@ -3,6 +3,39 @@
 Fast and efficient Rust implementation of ed25519 key generation, signing, and
 verification.
 
+# Benchmarks
+
+On an Intel i5 Sandy Bridge running at 2.6 GHz, with TurboBoost enabled (and
+also running in QubesOS with *lots* of other VMs executing), this code
+achieves the following performance benchmarks:
+
+    ∃!isisⒶwintermute:(release/0.1.0 *$)~/code/rust/ed25519 ∴ cargo bench
+    Finished release [optimized] target(s) in 0.0 secs
+    Running target/release/deps/ed25519-0135748522c518d8
+
+    running 5 tests
+    test ed25519::test::test_sign_verify ... ignored
+    test ed25519::test::test_unmarshal_marshal ... ignored
+    test ed25519::test::bench_key_generation ... bench:    54,837   ns/iter (+/- 11,613)
+    test ed25519::test::bench_sign           ... bench:    69,735   ns/iter (+/- 21,902)
+    test ed25519::test::bench_verify         ... bench:   183,891   ns/iter (+/- 75,304)
+
+    test result: ok. 0 passed; 0 failed; 2 ignored; 3 measured
+
+In comparision, the equivalent package in Golang performs as follows:
+
+    ∃!isisⒶwintermute:(master *=)~/code/go/src/github.com/agl/ed25519 ∴ go test -bench .
+    PASS
+    BenchmarkKeyGeneration     20000             85880 ns/op
+    BenchmarkSigning           20000             89115 ns/op
+    BenchmarkVerification      10000            212585 ns/op
+    ok      github.com/agl/ed25519  7.500s
+
+Making key generation, signing, and verification a rough average of one third
+faster, one fifth faster, and one eighth faster respectively.  Of course, this
+is just my machine, and these results—nowhere near rigorous—should be taken
+with a fistful of salt.
+
 # Installation
 
 To install, add the following to the dependencies section of your project's
@@ -17,3 +50,4 @@ Then, in your library or executable source, add:
 # TODO
 
  * Maybe add methods to make exporting keys for backup easier.
+ * Benchmark in comparison to the ed25519_ref10 code.