[PATCH] Modify README to add instructions re: installing guix from guix

[Alex Sassmannshausen <alex.sassmannshausen@gmail.com>]

Hi, 

Please find attach a tiny addition to the README to detail the
--with-libgcrypt-prefix option to be added to ./configure when building
guix from guix.

First patch, so please let me know if I made any mistakes.

Best wishes,

Alex

===File
~/Projects/guix/0001-Add-section-In-Case-of-Complications.patch===
From 9e953d321cae6a662c2b8bab8fa4ac665795d133 Mon Sep 17 00:00:00 2001
From: Alex Sassmannshausen <alex.sassmannshausen@gmail.com>
Date: Tue, 23 Apr 2013 08:56:31 +0200
Subject: [PATCH] Add section 'In Case of Complications'

Section contains sub-headings, the first of which details steps required to be carried out to install Guix using Guix. Specifically mention need to pass --with-libgcrypt-prefix to ./configure.
---
 README |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/README b/README
index 0943358..695be5c 100644
--- a/README
+++ b/README
@@ -137,3 +137,12 @@ but exposes all the API as Scheme.
   - The [[http://www.gnu.org/s/gsrc/][GNU Source Release Collection]] (GSRC) is a user-land software
     distribution; unlike Guix, it relies on core tools available on the
     host system
+* In Case of Complications
+** Guix from Guix
+   You can re-install (re-make && make install) Guix using a system that
+   already runs Guix. To do so:
+   - install the Guix dependencies (see 'Requirements' above) using Guix
+   - re-run the configure script passing it the option
+     --with-libgcrypt-prefix=$HOME/.guix-profile/
+   - run make
+   - run sudo make install
-- 
1.7.10.4

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