Updates README with spaceship collector advice

README.md

@@ -120,6 +120,30 @@ package { 'mime':
 }
 ```
 
+#### Caveat using the npm package provider
+
+Note: The npm provider won't be avaliable until the server has been marked as having the `npm` command avaliable.
+
+So the following code will not work:
+
+```puppet
+include ::node
+
+package { 'bower':
+  provider => 'npm'
+}
+```
+
+As the npm provider won't be avaliable until the next Puppet run.
+
+One solution for this is to add collectors to ensure that all packages with the `npm` provider happen after `::nodejs` has applied
+
+```puppet
+Class['::nodejs'] -> Package <| provider == 'npm' |>
+```
+
+Note that this can lead to dependency cycles and has implications for virtual resources. Use with caution.
+
 ### npm local packages
 
 nodejs::npm is used for the local installation of npm packages. It attempts to