docs: add local option for use command

README.md

@@ -53,6 +53,7 @@ Usage: nrm [options] [command]
     current                               Show current registry name
       -u  --show-url                        Show the registry URL instead of the name
     use [registry]                        Change registry to registry
+      -l  --local                           Switch local registry
     add <registry> <url> [home]           Add one custom registry
     login <registry> [value]              Set authorize information for a registry with a base64 encoded string or username and password
       -a  --always-auth                     Set is always auth