feat(nsc): add completion plugin

plugins/nsc/README.md

@@ -0,0 +1,11 @@
+# NSC plugin
+
+This plugin adds completion for the [NSC](https://github.com/nats-io/nsc).
+
+To use it, add `nsc` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... nsc)
+```
+
+This plugin does not add any aliases.