[PATCH 3 of 3] docs/installation: clarify root privileges requirement for 'pip install'

[Thomas De Schampheleire]

# HG changeset patch
# User Thomas De Schampheleire <thomas.de.schampheleire at gmail.com>
# Date 1426366315 -3600
#      Sat Mar 14 21:51:55 2015 +0100
# Node ID b5efe92cea65b44e102a90508db3d53f5919466f
# Parent  f5e05f4a8bff420c63924b3764fcf33d162624ed
docs/installation: clarify root privileges requirement for 'pip install'

diff --git a/docs/installation.rst b/docs/installation.rst
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -34,6 +34,12 @@
 
     pip install kallithea
 
+Note that this method requires root privileges. When installing as a regular
+user, you can use::
+
+    pip install --user kallithea
+
+or (recommended) install Kallithea in a virtualenv (next section).
 
 Installation in virtualenv
 --------------------------