update installer examples

README.md

@@ -86,10 +86,17 @@ The install path will be the preceding `lib/node_modules`
 (which you usually want to be the same as `NPM_CONFIG_PREFIX` anyway).
 
 ```bash
-export NPM_CONFIG_PREFIX=/tmp/user/local
-export NODE_PATH=/tmp/user/local/lib/node_modules
+export NPM_CONFIG_PREFIX=/tmp/usr/local
+export NODE_PATH=/tmp/usr/local/lib/node_modules
 ```
 
+A more realistic example for a self-contained node app:
+```bash
+export NPM_CONFIG_PREFIX=/opt/my-app
+export NODE_PATH=/opt/my-app/lib/node_modules
+```
+
+
 ```bash
 curl -fsSL https://bit.ly/node-installer -o ./node-installer.sh; bash ./node-installer.sh --dev-deps
 ```