made it explicit not to use plain TRestServer

- see https://synopse.info/forum/viewtopic.php?id=6781

src/mormot.commit.inc

@@ -1 +1 @@
-'2.2.6621'
+'2.2.6622'

src/rest/mormot.rest.server.pas

@@ -1747,9 +1747,10 @@   TRestServerUriPagingParameters = record
   TOnInternalInfo = procedure(Sender: TRestUriContext;
     var Info: TDocVariantData) of object;
 
-  /// a generic REpresentational State Transfer (REST) server
+  /// a generic/abstract REpresentational State Transfer (REST) server
   // - descendent must implement the protected EngineList() Retrieve() Add()
-  // Update() Delete() methods
+  // Update() Delete() methods - so if you want a REST server with no ORM
+  // (e.g. for a pure SOA server), use (or inherit) TRestServerFullMemory
   // - automatic call of this methods by a generic Uri() RESTful function
   // - any published method of descendants must match TOnRestServerCallBack
   // prototype, and is expected to be thread-safe