Document new feature to Elixir's Oban integration (#11123)

docs/platforms/elixir/integrations/oban/index.mdx

@@ -46,5 +46,13 @@ def before_send(event) do
 end
 ```
 
+The Oban job itself (an [`Oban.Job` struct](https://hexdocs.pm/oban/Oban.Job.html)) is also available inside the event's `:integration_meta` field, under:
+
+```elixir
+event.integration_meta[:oban][:job]
+```
+
+You can use this for more complex filtering logic based on number of attempts and such.
+
 See <Link to="/platforms/elixir/configuration/filtering">the documentation for event callbacks</Link>.
 </Alert>