Update README.md

Author: ts-navghane

README.md

@@ -7,3 +7,11 @@ This plugin enable Mautic 5 to run Sparkpost as a transport.
 
 #### Mautic Mailer DSN Scheme
 `mautic+sparkpost+api`
+
+#### Mautic Mailer DSN Example
+`mautic+sparkpost+api://:<api_key>@<host>:<port>?region=us`
+- api_key: Get Sparkpost API key from https://app.sparkpost.com/account/api-keys/create
+- host: Your Sparkpost host
+- port: Your Sparkpost port
+- options:
+  - region: Your Sparkpost region