Update benchmark instructions

.github/CONTRIBUTING.md

@@ -85,10 +85,18 @@ yarn compile --watch
 
 ## Benchmarks
 
-To run the performance benchmarks in a browser (opening `./packages/benchmarks/index.html`):
+To run the benchmarks locally:
 
 ```
 yarn benchmarks
+open ./packages/benchmarks/dist/index.html
+```
+
+To develop against these benchmarks:
+
+```
+yarn compile --watch
+yarn benchmarks --watch
 ```
 
 ### New Features

packages/benchmarks/README.md

@@ -5,7 +5,7 @@ Try the [benchmarks app](https://necolas.github.io/react-native-web/benchmarks)
 To run the benchmarks locally:
 
 ```
-yarn benchmark
+yarn benchmarks
 open ./packages/benchmarks/dist/index.html
 ```
 
@@ -13,7 +13,7 @@ Develop against these benchmarks:
 
 ```
 yarn compile --watch
-yarn benchmark --watch
+yarn benchmarks --watch
 ```
 
 ## Notes