Document embedded API surface

lib/parrhesia.ex

@@ -1,17 +1,27 @@
 defmodule Parrhesia do
   @moduledoc """
-  Documentation for `Parrhesia`.
+  Parrhesia is a Nostr relay runtime that can run standalone or as an embedded OTP service.
+
+  For embedded use, the main developer-facing surface is `Parrhesia.API.*`.
+  Start with:
+
+  - `Parrhesia.API.Events`
+  - `Parrhesia.API.Stream`
+  - `Parrhesia.API.Admin`
+  - `Parrhesia.API.Identity`
+  - `Parrhesia.API.ACL`
+  - `Parrhesia.API.Sync`
+
+  The host application is responsible for:
+
+  - setting `config :parrhesia, ...`
+  - migrating the configured Parrhesia repos
+  - deciding whether to expose listeners or use only the in-process API
+
+  See `README.md` and `docs/LOCAL_API.md` for the embedding model and configuration guide.
   """
 
-  @doc """
-  Hello world.
-
-  ## Examples
-
-      iex> Parrhesia.hello()
-      :world
-
-  """
+  @doc false
   def hello do
     :world
   end