update readme to support functions and hashes instead of only functions

Author: Knerio

README.md

@@ -31,7 +31,7 @@ require "code0/identities"
 begin
 
   identity = Code0::Identities::Provider::Discord.new(
-    -> {
+    {
       redirect_uri : "http://localhost:8080/redirect",
         client_id : "id"
       client_secret : "xxxx"
@@ -70,4 +70,25 @@ identity_provider.load_identity(:gitlab, params)
 
 identity_provider.load_identity(:my_custom_gitlab_provider, params)
 
+```
+
+We also support passing in a function as a configuration instead of a hash
+
+```ruby
+
+def get_identity
+  provider = Code0::Identities::Provider::Discord.new(fetch_configuration)
+
+  provider.load_identity(params)
+end
+
+def fetch_configuration
+  # Do some database action, to dynamicly load the configuration
+  # {
+  redirect_uri : "http://localhost:8080/redirect",
+    client_id : "some dynamic value"
+  client_secret : "xxxx"
+  }
+end
+
 ```