repl documentation, adds @asmeurer suggestions

docs/docs/repl.rst

@@ -1,8 +1,18 @@
 .. include:: ../global.rst
 
-How to use Jedi from Python interpreter
-=======================================
+Jedi autocompletion in the Python interpreter
+=============================================
+
+There are two different options how you can use Jedi autocompletion in
+your Python interpreter. One with your custom ``$HOME/.pythonrc.py`` file
+and one that uses ``PYTHONSTARTUP``.
+
+Using ``PYTHONSTARTUP``
+-----------------------
 
 .. automodule:: jedi.replstartup
 
+Using a custom ``$HOME/.pythonrc.py``
+-------------------------------------
+
 .. autofunction:: jedi.utils.setup_readline

jedi/replstartup.py

@@ -1,6 +1,4 @@
 """
-``PYTHONSTARTUP`` to use Jedi in your Python interpreter.
-
 To use Jedi completion in Python interpreter, add the following in your shell
 setup (e.g., ``.bashrc``)::
 

jedi/utils.py

@@ -93,11 +93,14 @@ def setup_readline():
     Install Jedi completer to :mod:`readline`.
 
     This function setups :mod:`readline` to use Jedi in Python interactive
-    shell.  If you want to use custom ``PYTHONSTARTUP`` file, you can call
-    this function like this:
+    shell.  If you want to use a custom ``PYTHONSTARTUP`` file (typically
+    ``$HOME/.pythonrc.py``), you can add this piece of code:
 
-    >>> from jedi.utils import setup_readline
-    >>> setup_readline()
+    >>> try:
+    >>>     from jedi.utils import setup_readline
+    >>>     setup_readline()
+    >>> except ImportError:
+    >>>     print('Install Jedi with pip! No autocompletion otherwise.')
 
     """
     try: