add benchmarks to root readme

Author: lukeed

readme.md

@@ -11,6 +11,64 @@
   _The standalone CLI application, allowing for instant previews of static sites._
 
 
+
+## Benchmarks
+
+All benchmarks are taken using the same [Polka](https://github.com/lukeed/polka) application on Node v8.9.0.
+
+Please note that the actual numbers don't really matter; however, the percentage differences between them do!
+
+***File Exists***
+
+```
+$ wrk -t8 -c100 -d10s http://localhost:3000/
+```
+
+```
+serve-static
+    Thread Stats   Avg      Stdev     Max   +/- Stdev
+        Latency     8.74ms  596.13us  14.44ms   79.26%
+        Req/Sec     1.38k    56.04     1.45k    69.62%
+      109872 requests in 10.02s, 40.66MB read
+    Requests/sec:  10969.49
+    Transfer/sec:      4.06MB
+
+sirv
+    Thread Stats   Avg      Stdev     Max   +/- Stdev
+        Latency     7.87ms    2.53ms  15.59ms   81.37%
+        Req/Sec     1.53k    69.36     2.07k    71.25%
+      122047 requests in 10.03s, 33.87MB read
+    Requests/sec:  12174.15
+    Transfer/sec:      3.38MB
+```
+
+***File Missing***
+
+```
+$ wrk -t8 -c100 -d10s http://localhost:3000/foobar
+```
+
+```
+serve-static
+    Thread Stats   Avg      Stdev     Max   +/- Stdev
+        Latency     4.00ms  257.09us   7.81ms   76.04%
+        Req/Sec     3.01k    65.66     3.15k    74.62%
+      239800 requests in 10.01s, 26.30MB read
+      Non-2xx or 3xx responses: 239800
+    Requests/sec:  23962.46
+    Transfer/sec:      2.63MB
+
+sirv
+    Thread Stats   Avg      Stdev     Max   +/- Stdev
+        Latency     2.89ms  256.70us   6.62ms   72.19%
+        Req/Sec     4.17k   157.94     4.93k    75.22%
+      334715 requests in 10.10s, 44.69MB read
+      Non-2xx or 3xx responses: 334715
+    Requests/sec:  33130.72
+    Transfer/sec:      4.42MB
+```
+
+
 ## License
 
 MIT © [Luke Edwards](https://lukeed.com)