Revert "DOCS/man/input: document that shutdown is sent when scripts terminate"

This reverts commit 86383aef95.

shutdown isn't actually sent on exit() but only with internal options,
e.g. set osc no, which isn't relevant for users.

DOCS/man/input.rst

@@ -1754,8 +1754,8 @@ This list uses the event name field value, and the C API symbol in brackets:
     Start of playback after seek or after file was loaded.
 
 ``shutdown`` (``MPV_EVENT_SHUTDOWN``)
-    Sent when the player quits or when a script terminates. Normally handled
-    automatically. See `Details on the script initialization and lifecycle`_.
+    Sent when the player quits, and the script should terminate. Normally
+    handled automatically. See `Details on the script initialization and lifecycle`_.
 
 ``log-message`` (``MPV_EVENT_LOG_MESSAGE``)
     Receives messages enabled with ``mpv_request_log_messages()`` (Lua:

DOCS/man/javascript.rst

@@ -404,3 +404,6 @@ non-negligible duration to complete, so we re-calculate ``wait`` afterwards.
 
 ``mp.peek_timers_wait()`` returns the same values as ``mp.process_timers()``
 but without doing anything. Invalid result if called from a timer callback.
+
+Note: ``exit()`` is also registered for the ``shutdown`` event, and its
+implementation is a simple ``mp.keep_running = false``.