Add a README for the examples/ directory

Author: evancz

examples/README.md

@@ -0,0 +1,11 @@
+# Examples
+
+To compile these examples locally, run the following terminal commands:
+
+```
+git clone https://github.com/elm/browser.git
+cd browser/examples
+elm reactor
+```
+
+Now go to [`http://localhost:8000`](http://localhost:8000) and navigate to whatever Elm file you want to see.