chore(docs): improve docs

Author: puzpuzpuz

README.md

@@ -2,7 +2,11 @@
 
 Golang client for QuestDB's Influx Line Protocol over TCP.
 
-Tested against QuestDB 6.4 and newer versions.
+Features:
+* Context-aware API.
+* Optimized for batch writes.
+* Supports TLS encryption and [ILP authentication](https://questdb.io/docs/reference/api/ilp/authenticate).
+* Tested against QuestDB 6.4 and newer versions.
 
 ## Usage
 

sender.go

@@ -58,6 +58,9 @@ const (
 
 // LineSender allows you to insert rows into QuestDB by sending ILP
 // messages.
+//
+// Each sender corresponds to a single TCP connection. A sender
+// should not be called concurrently by multiple goroutines.
 type LineSender struct {
 address string
 tlsMode tlsMode