Update README.md

Author: wangfenjin

examples/node/README.md

@@ -1,10 +1,14 @@
 # node example
 
 ```
-# download lib from github
+# install dependency
 npm install
-# run example
+# download lib from github
+npm download
+# run example using downloaded lib
 npm run p
+# run example and set the ext_path and dict_path
+npm run p -- --ext_path=/path/to/libsimple/ --dict_path=/path/to/dict/
 # remove build folder
 npm run clean
 ```