Update README.md

Signed-off-by: Adam Fowler <adamfowler71@gmail.com>

Author: adam-fowler

README.md

@@ -49,4 +49,8 @@ let value = try getResponse.get()
 
 ## Redis compatibility
 
-As Valkey is a fork of Redis v7.2.4, valkey-swift is compatible with Redis databases up to v7.2.4. There is a chance that v7.2.4 features will still be compatible in later versions of Redis, but these are now considered two different projects and they will diverge. valkey-swift uses the RESP3 protocol.
+As Valkey is a fork of Redis v7.2.4, valkey-swift is compatible with Redis databases up to v7.2.4. There is a chance that v7.2.4 features will still be compatible in later versions of Redis, but these are now considered two different projects and they will diverge. valkey-swift uses the RESP3 protocol.
+
+## Documentation
+
+User guides and reference documentation for valkey-swift can be found on the [Swift Package Index](https://swiftpackageindex.com/valkey-io/valkey-swift/main/documentation/valkey).