docs: add readme

README.md

@@ -85,10 +85,20 @@ $ egg-bin dev
 
 Debug egg app with [V8 Inspector Integration](https://nodejs.org/api/debugger.html#debugger_v8_inspector_integration_for_node_js).
 
+automatically detect the protocol used by the targeted runtime, 8.0+ the new 'inspector' protocol is used.
+
+use [inspector-proxy](https://github.com/whxaxes/inspector-proxy) to proxy worker debug, so you don't need to worry about reload.
+
 ```bash
-$ egg-bin debug
+$ egg-bin debug --debug-port=9229 --proxy=9999
 ```
 
+##### options
+
+- all `egg-bin dev` options is accepted.
+- `--proxy=9999` worker debug proxy port.
+
+
 ### test
 
 Using [mocha] with [co-mocha] to run test.