Changed updated readme file

README.md

@@ -3,7 +3,7 @@
 Inspired by the [official PHP SDK](https://github.com/invoiceninja/sdk-php), a
 Python wrapper for Invoice Ninja's REST API.
 
-# Models
+## Model Projects
 
 Projects to look to for guidance:
 
@@ -13,3 +13,13 @@ Projects to look to for guidance:
 * [python-vaultwarden](https://github.com/numberly/python-vaultwarden)
     - simple python wrapper for the bitwarden/vaultwarden
 
+## How to use
+
+Let see some basic usage:
+```
+>>> # Import client from module
+>>> from pyinvoiceninja import InvoiceNinjaClient
+>>> # 
+>>> client = InvoiceNinjaClient(base_url='https://ninja.instance/api/v1')
+```
+