[readme] Stop removing spaces from nvm_path

It breaks switching version of node through nvm in directories with space somewhere in it's path.
diff --git a/README.md b/README.md
index ca88148..dcb1b2d 100644
--- a/README.md
+++ b/README.md
@@ -463,7 +463,7 @@
 
 cdnvm(){
     cd "$@";
-    nvm_path=$(find-up .nvmrc | tr -d '[:space:]')
+    nvm_path=$(find-up .nvmrc | tr -d '\n')
 
     # If there are no .nvmrc file, use the default nvm version
     if [[ ! $nvm_path = *[^[:space:]]* ]]; then