Improve logging and debugging document

doc/source/index.rst

@@ -402,8 +402,8 @@ web client.  See `emacslisp.py`_ for more details.
 Reporting issue
 ---------------
 
-Error logging
-^^^^^^^^^^^^^
+Logging
+^^^^^^^
 
 Sometime more information that the ``*Message*`` buffer provides is
 needed to debug.
@@ -429,18 +429,35 @@ needed to debug.
    If it is too long, you can use paste bin service such as
    `gist <https://gist.github.com/>`_.
 
+websocket.el
+""""""""""""
+
+websocket.el has its logging buffer.  Sometime its useful to see its
+log.  This is how to do that.
+
+1. ``(require 'ein-dev)``
+2. ``(setq websocket-debug t)`` or call :el:symbol:`ein:dev-start-debug`.
+3. Then do the operation which causes the problem.
+4. Go to log buffer using
+   :el:symbol:`ein:dev-pop-to-debug-shell` and
+   :el:symbol:`ein:dev-pop-to-debug-iopub`.
+   These command must be called in the notebook buffer.
+
 Debugging
 ^^^^^^^^^
 
 If you are interested in debugging EIN, you should start it with
-loading :el:symbol:`ein-dev` package and then execute the command
-:el:symbol:`ein:dev-start-debug`.
+loading :el:symbol:`ein-dev` package [#]_ and then executing the
+command :el:symbol:`ein:dev-start-debug`.
 This command sets :el:symbol:`debug-on-error` to ``t`` and do some
 patching to debugger.  This patching is required because printing EWOC
 objects freezes Emacs otherwise.  It also changes log level to
 log everything the log buffer.  You can reset the patch and log level
 with :el:symbol:`ein:dev-stop-debug`.
 
+.. [#] You can set the variable :el:symbol:`ein:load-dev` to
+   :el:symbol:`t` to load ein-dev.el always.
+
 
 Change Log
 ==========