docs(elixir): Only recommend Sentry.PlugCapture for Cowboy applications

Author: martosaur

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

@@ -6,18 +6,16 @@ sidebar_order: 10
 
 You can capture errors in [Plug](https://github.com/elixir-plug/plug) and [Phoenix](https://phoenixframework.org) applications with `Sentry.PlugContext` and `Sentry.PlugCapture`.
 
-`Sentry.PlugContext` adds contextual metadata from the current request, which is then included in errors that are captured and reported by `Sentry.PlugCapture`.
+`Sentry.PlugContext` adds contextual metadata from the current request to the reported errors that happen during Plug execution. For [Cowboy](https://hex.pm/packages/cowboy) applications, an additional plug `Sentry.PlugCapture` is required to ensure this metadata propagates properly.
 
 ## Phoenix Configuration
 
 If you are using Phoenix, follow these steps to add the Plug integration:
 
-  1. Add `Sentry.PlugCapture` above the `use Phoenix.Endpoint` line in your endpoint file.
   1. Add `Sentry.PlugContext` below `Plug.Parsers`.
 
 ```elixir {diff}
 defmodule MyAppWeb.Endpoint
-+  use Sentry.PlugCapture
    use Phoenix.Endpoint, otp_app: :my_app
 
    # ...
@@ -30,6 +28,16 @@ defmodule MyAppWeb.Endpoint
 +  plug Sentry.PlugContext
 ```
 
+  2. If you're using Cowboy, add `Sentry.PlugCapture` above the `use Phoenix.Endpoint` line in your endpoint file.
+
+```elixir {diff}
+defmodule MyAppWeb.Endpoint
++  use Sentry.PlugCapture
+   use Phoenix.Endpoint, otp_app: :my_app
+
+   # ...
+```
+
 If you're also using [Phoenix LiveView](https://github.com/phoenixframework/phoenix_live_view), consider also setting up your LiveViews to use the `Sentry.LiveViewHook` hook (available in the Sentry SDK versions `10.5.0` and higher):
 
 ```elixir
@@ -78,18 +86,26 @@ end
 
 If you have a non-Phoenix application, follow these steps to configure the Plug integration:
 
-  1. Add `Sentry.PlugCapture` at the top of your Plug application.
   1. Add `Sentry.PlugContext` below `Plug.Parsers` (if it is in your stack).
 
 ```elixir {diff}
  defmodule MyApp.Router do
    use Plug.Router
-+  use Sentry.PlugCapture
 
    # ...
 
    plug Plug.Parsers,
      parsers: [:urlencoded, :multipart]
 
 +  plug Sentry.PlugContext
+```
+
+  2. If you're using Cowboy, add `Sentry.PlugCapture` at the top of your Plug application.
+
+```elixir {diff}
+ defmodule MyApp.Router do
+   use Plug.Router
++  use Sentry.PlugCapture
+
+   # ...
 ```