Document the new environment variable newline handling in my_init

README.md

@@ -227,7 +227,7 @@ During startup, before running any [startup scripts](#running_startup_scripts),
 
 For example, here's how you can define an environment variable from your Dockerfile:
 
-    RUN echo -n Apachai Hopachai > /etc/container_environment/MY_NAME
+    RUN echo Apachai Hopachai > /etc/container_environment/MY_NAME
 
 You can verify that it works, as follows:
 
@@ -237,6 +237,12 @@ You can verify that it works, as follows:
     # echo $MY_NAME
     Apachai Hopachai
 
+**Handling newlines**
+
+If you've looked carefully, you'll notice that the 'echo' command actually prints a newline. Why does $MY_NAME not contain a newline then? It's because `my_init` strips the trailing newline, if any. If you intended on the value having a newline, you should add *another* newline, like this:
+
+    RUN echo -e "Apachai Hopachai\n" > /etc/container_environment/MY_NAME
+
 <a name="envvar_dumps"></a>
 #### Environment variable dumps