update readme

README.md

@@ -14,7 +14,7 @@ Distributed rate limiting with pluggable storage for storing counters state.
 c, _ := counter.New(1, time.Millisecond*100)
 // Increment counter and get remainder
 if v, err := c.Count("key"); err != nil {
-	if e, ok := err.(locker.TTLError); ok {
+	if e, ok := err.(counter.TTLError); ok {
 		// Use e.TTL() if need
 	} else {
 		// Handle err
@@ -31,4 +31,4 @@ if v, err := c.Count("key"); err != nil {
 - [example](./examples/counter-gateway-default/main.go) usage with default [gateway](./gateway/memory/memory.go)
 - [example](./examples/counter-gateway-memory/main.go) usage with memory [gateway](./gateway/memory/memory.go)
 - [example](./examples/counter-gateway-redis/main.go) usage with [Redis](https://redis.io) [gateway](./gateway/redis/redis.go)
-- [example](./examples/counter-with-retry/main.go) usage with [retry](https://github.com/da440dil/go-trier)
+- [example](./examples/counter-with-retry/main.go) usage with [retry](https://github.com/da440dil/go-trier)