Update README.md

Author: mobizt

README.md

@@ -16,6 +16,10 @@ The RTDB (Realtime database), FCM (Cloud Messaing) and core code used in `Fireba
 
 The `FirebaseESP8266` and `FirebaseESP32` libraries are the old and limited features Firebase client library while `Firebase-ESP-Client` is the newver version of Firebase client library that developed to support more Firebase services.
 
+Try the beta version of new async [FirebaseClient](https://github.com/mobizt/FirebaseClient) library which is faster and more reliable.
+
+The new async [FirebaseClient](https://github.com/mobizt/FirebaseClient) is currently support Realtime Database.
+
 ## Contents
 
 [1. Features](#features)
@@ -1835,4 +1839,4 @@ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.