Fixed make install from read-only build directory (spotted by Marcus
Meissner).

diff --git a/README b/README
index 5fd7bec..c18fae8 100644
--- a/README
+++ b/README
@@ -195,7 +195,7 @@
 Some documentation (various Wine Guides etc.) can be found in the
 documentation/ directory (apart from also being available on WineHQ).
 
-If you want to process the SGML files in there, then you can run "make"
+If you want to process the SGML files in there, then you can run "make doc"
 in the documentation/ directory.
 Doing so requires the sgml tools package (for db2html, db2ps, db2pdf) named:
 Debian:		docbook-utils