Update prerequisites for RHEL in README

In RHEL a full texlive's set of packages is needed to build a documentation.

Signed-off-by: Yuriy Kolerov <[email protected]>
Signed-off-by: Anton Kolesov <[email protected]>

Author: kolerov

README.md

@@ -43,11 +43,17 @@ On Ubuntu 12.04/14.04 LTS those can be installed with following command (as root
     # apt-get install texinfo byacc flex libncurses5-dev zlib1g-dev \
       libexpat1-dev libx11-dev texlive build-essential git
 
-On Fedora 17 those can be installed those with following command (as root):
+On RHEL 6/7 those can be installed with following command (as root):
 
     # yum groupinstall "Development Tools"
     # yum install texinfo-tex byacc flex ncurses-devel zlib-devel expat-devel \
-      libX11-devel git
+      libX11-devel git texlive-\*
+
+It's necessary to install a full `texlive` set in RHEL 6/7 (`texlive-*`) to
+prevent errors due to missing TeX fonts while building a documentation. Since
+`texlive-*` installs a big set of large packets (hundreds of megabytes) it's
+possible to omit `texlive-*` in `yum install` and instead pass `--no-pdf`
+option to the `build-all.sh` script if the documentation is not required.
 
 GCC depends on the GMP, MPFR and MPC packages, however there are problems with
 availability of those packages on the RHEL/CentOS 6 systems (packages has too