Add a POST echo example

examples/echo_post/README.md

@@ -0,0 +1,24 @@
+Cowboy POST Echo
+================
+
+To compile this example you need rebar in your PATH.
+
+Type the following command:
+```
+$ rebar get-deps compile
+```
+
+You can then start the Erlang node with the following command:
+```
+./start.sh
+```
+
+Then point your browser to the indicated URL. You can change
+the GET parameter to check that the handler is echoing properly.
+
+Then run the following command, replacing STRING_TO_ECHO by the
+string you want to echo. Check the ```curl_post.sh``` file for details.
+
+```
+./curl_post.sh STRING_TO_ECHO
+```