Update README.markdown

Specifies the lines that will be added by the installation script.

README.markdown

@@ -48,6 +48,11 @@ wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.31.3/install.sh |
 
 <sub>The script clones the nvm repository to `~/.nvm` and adds the source line to your profile (`~/.bash_profile`, `~/.zshrc`, `~/.profile`, or `~/.bashrc`).</sub>
 
+```sh
+export NVM_DIR="$HOME/.nvm"
+[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh" # This loads nvm
+```
+
 You can customize the install source, directory, profile, and version using the `NVM_SOURCE`, `NVM_DIR`, `PROFILE`, and `NODE_VERSION` variables.
 Eg: `curl ... | NVM_DIR=/usr/local/nvm bash` for a global install.