Update docs

lib/elixir/lib/gen_server.ex

@@ -8,17 +8,6 @@ defmodule GenServer do
   will have a standard set of interface functions and include functionality for
   tracing and error reporting. It will also fit into a supervision tree.
 
-  ```mermaid
-  graph TD
-      GenServer
-      GenServer -. reply -.-> A
-      GenServer -. reply -.-> B
-      GenServer -. reply -.-> C
-      A(Client #1) -- request --> GenServer
-      B(Client #2) -- request --> GenServer
-      C(Client #3) -- request --> GenServer
-  ```
-
   ## Example
 
   The GenServer behaviour abstracts the common client-server interaction.

lib/elixir/lib/module.ex

@@ -326,8 +326,17 @@ defmodule Module do
   ### `@nifs` (since v1.16.0)
 
   A list of functions and their arities which will be overridden
-  by a native implementation (NIF). See the Erlang documentation
-  for more information: https://www.erlang.org/doc/man/erl_nif
+  by a native implementation (NIF).
+
+      defmodule MyLibrary.MyModule do
+        @nifs [foo: 1, bar: 2]
+
+        def foo(arg1), do: :erlang.nif_error(:not_loaded)
+        def bar(arg1, arg2), do: :erlang.nif_error(:not_loaded)
+      end
+
+  See the Erlang documentation for more information:
+  https://www.erlang.org/doc/man/erl_nif
 
   ### `@on_definition`