chore(docs): add godoc link

Author: puzpuzpuz

README.md

@@ -1,3 +1,5 @@
+[![GoDoc reference](https://img.shields.io/badge/godoc-reference-blue.svg)](https://pkg.go.dev/github.com/questdb/go-questdb-client)
+
 # go-questdb-client
 
 Golang client for QuestDB's Influx Line Protocol over TCP.
@@ -8,6 +10,8 @@ Features:
 * Supports TLS encryption and [ILP authentication](https://questdb.io/docs/reference/api/ilp/authenticate).
 * Tested against QuestDB 6.4 and newer versions.
 
+Documentation is available [here](https://pkg.go.dev/github.com/questdb/go-questdb-client).
+
 ## Usage
 
 ```go