Docs: add troubleshooting - slow page help

* Due to: #704

docs/troubleshooting.md

@@ -79,4 +79,31 @@ In the specific `bootstrap` example you could override the default bootstrap `"p
 
 !!!
 
+==- Slow Last Page
+
+There has been a report of a slow last page that has not been reproduced ([#696](https://github.com/ddnexus/pagy/pull/696)). 
+
+If you experience this rare case, try the following:
+
+
+```rb
+## override pagy_get_items
+ 	def pagy_get_items(collection, pagy)      
+      collection.offset(pagy.offset).limit(pagy.in)
+    end
+```
+
+!!!warning Will not work with MS SQL Server
+
+If you are using MS SQL Server and there is a possibility of having a collection with zero items, then the above [will throw an exception](https://github.com/ddnexus/pagy/issues/704). 
+
+In those cases, consider the following:
+
+```rb
+## override pagy_get_items
+ 	def pagy_get_items(collection, pagy)      
+ 		collection.offset(pagy.offset).limit(pagy.in > 0 ? pagy.in :  pagy.items )
+ 	end
+```
+!!!
 ===