Add documentation for paginated and multi level request

docs/usage/paginated.md

@@ -0,0 +1,19 @@
+Paginated request
+=================
+
+```kotlin
+import fr.postgresjson.connexion.Paginated
+import fr.postgresjson.connexion.Requester
+import java.util.UUID
+
+class Article(val id: UUID, val name: String)
+
+val request: Requester = TODO()
+val article: Paginated<Article> = requester
+    .getFunction("find_articles")
+    .select(
+        page = 1, 
+        limit = 10, 
+        "id" to "4a04820e-f880-4d80-b1c9-aeacccb24977"
+    )
+```