feat: 🎸 add NFSv4 data types

Author: streamich

src/nfs/v4/README.md

@@ -1 +1,14 @@
 # NFSv4 Protocol Implementation
+
+This directory contains an implementation of the NFSv4 protocol data structures based on RFC 7530 and RFC 7531.
+
+## Overview
+
+NFSv4 is a distributed file system protocol that integrates:
+- Traditional file access operations
+- File locking (integrated, unlike NFSv3 which used separate NLM protocol)
+- Mount protocol (integrated, unlike NFSv3 which used separate MOUNT protocol)
+- Strong security with RPCSEC_GSS
+- COMPOUND operations for reduced latency
+- Client caching and delegations
+- Internationalization support