Add documentation about the new REPL functions

docs/index.rst

@@ -41,6 +41,7 @@ Pretty is released under the terms of the `Apache Software License 2.0 <http://w
 
    ansi
    exceptions
+   repl
    lein-plugin
    binary
    columns

docs/repl.rst

@@ -0,0 +1,54 @@
+REPL
+====
+
+Pretty includes some useful REPL utilities in the ``io.aviso.repl`` namespace.
+
+Primarily, the ``install-pretty-exceptions`` function overrides several
+internal Clojure functions to enable
+:doc:`formatted exceptions <exceptions>`.
+This function is normally invoked for you
+when Pretty is
+:doc:`used as a Leiningen plugin <lein-plugin>`.
+
+The remaining functions exist to help you make things pretty
+that *don't* originate in the REPL. You will often see output in logs: EDN data perhaps,
+or often, raw exceptions.
+
+If you have a REPL running, you can use the following functions to get a better view
+of that data:
+
+copy
+----
+
+The ``copy`` function will return the current contents of the system clipboard
+as a string.
+This requires that AWT is running.
+On OS X, you will see a window for your application start when you first invoke this function
+
+The ``pretty-print`` and ``format-exception`` functions can be invoked
+with no arguments, in which case the call to ``copy`` happens automatically.
+
+Consult the API documentation for more details.
+
+pretty-print
+------------
+
+This will pretty-print the contents of the clipboard; the clipboard text is parsed as EDN.
+
+format-exception
+----------------
+
+This will parse a normal Java stack trace and format it for readability.
+
+paste
+-----
+
+This will copy as string back on to the clipboard, so it can be pasted into
+another window.
+
+.. code-block:: clojure
+
+    (use 'io.aviso.repl)
+
+    (-> (copy) format-exception paste)
+