migrates everything from ipip's branch

apps/temp-docs/docs/javascript/using-modifiers.mdx

@@ -0,0 +1,13 @@
+---
+id: using-modifiers
+title: "Using Modifiers"
+slug: using-modifiers
+custom_edit_url: https://github.com/supabase/supabase/edit/master/web/spec/supabase.yml
+---
+
+import Tabs from '@theme/Tabs';
+import TabsPanel from '@theme/TabsPanel';
+
+Modifiers can be used on `select()` queries. 
+
+If a Postgres function returns a table response, you can also apply modifiers to the `rpc()` function.