update readme with more instructions

Signed-off-by: James Sturtevant <jstur@microsoft.com>

Author: jsturtevant

README.md

@@ -80,4 +80,11 @@ You don't have to install this as a plugin via krew.  You can also download and
 
 ```bash
 ./kubectl-windows-debug <node-name>
+```
+
+You can also use it as a manual plugin by coping it to a location on your `PATH`:
+
+```
+cp kubectl-windows-debug /usr/local/bin
+kubectl windows-debug
 ```