change npm link to npm install as it's cleaner.

Author: Dave Conway-Jones

docs/creating-nodes/packaging.md

@@ -31,16 +31,16 @@ directory, or they could each be placed in their own sub-directory.
 
 ### Testing a node module locally
 
-To test a node module locally, the `npm link` command can be used. This allows you
-to develop the node in a local directory and have it linked into a local node-red
-install, as if it had been npm installed.
+To test a node module locally, the [`npm install <folder>`](https://docs.npmjs.com/cli/install) command can be used. This allows you
+to develop the node in a local directory and have it linked into a local node-red install during development.
 
-1. in the directory containing the node's `package.json` file, run: `sudo npm link`.
-2. in your node-red user directory, typically `~/.node-red` run: `npm link <name of node module>`.
+In your node-red user directory, typically `~/.node-red`, run:
 
-This creates the appropriate symbolic links between the two directories so Node-RED
+    npm install <path to location of node module>
+
+This creates the appropriate symbolic link to the directory so that Node-RED
 will discover the node when it starts. Any changes to the node's file can be picked
-up by simply restarting Node-RED.
+up by simply restarting Node-RED. 
 
 ### package.json