feat(backend): relay contact requests to SMTP server

backend/settings/base.yaml

@@ -3,7 +3,11 @@ application:
   version: "0.1.0"
 
 email:
-  host: localhost
+  host: email.example.com
+  port: 587
   user: user
   from: Contact Form <noreply@example.com>
   password: hunter2
+  recipient: Admin <user@example.com>
+  starttls: false
+  tls: false

backend/settings/development.yaml

@@ -5,4 +5,12 @@ application:
   protocol: http
   host: 127.0.0.1
   base_url: http://127.0.0.1:3100
-  name: "com.phundrak.backend.prod"
+  name: "com.phundrak.backend.dev"
+
+email:
+  host: localhost
+  port: 1025
+  user: ""
+  password: ""
+  tls: false
+  starttls: false