Update README.md

Provided additional info about ReCAPTCHA setup

README.md

@@ -206,7 +206,6 @@ On some Windows machines, there might be issues, in that case try:
 
 `celery -A forum worker --loglevel=info -P eventlet`
 
-
 ### Node JS  frontend server
 - Setup frontend .env
 > Setup frontend .env
@@ -222,6 +221,22 @@ PORT=8080 npm start
 or
 PORT=8080 npm restart
 ```
+
+### Google ReCAPTCHA
+The project is currently using ReCAPTCHA V2 Invisible. Note that if the free monthly Google quota expires, users will be able to sign in and sign up without ReCAPTCHA verification.
+
+For proper ReCAPTCHA setup provide public and private keys from Google:
+
+Add in BackEnd .env
+```.env 
+RECAPTCHA_PRIVATE_KEY = "your-private-key"
+```
+
+Add in FrontEnd .env
+```.env 
+REACT_APP_RECAPTCHA_SITE_KEY = "your-public-key"
+```
+
 ### How to run Docker
 
 - Setup Docker  
@@ -332,4 +347,4 @@ Reach out to me at one of the following places!
 [![License](http://img.shields.io/:license-mit-blue.svg?style=flat-square)](http://badges.mit-license.org)
 
 - **[MIT license](http://opensource.org/licenses/mit-license.php)**
-- Copyright 2020 © <a href="https://softserve.academy/" target="_blank"> SoftServe IT Academy</a>.
+- Copyright 2020 © <a href="https://softserve.academy/" target="_blank"> SoftServe IT Academy</a>.