Remove deprecated pdf guide and mention deprecation in tex source.

gen_doc/LaTeX/gettingStartedFAuST-version2_1.tex

 \documentclass[a4paper,11pt]{report}
 \author{Adrien Leman; Nicolas Bellot}
 \def \FAuST {FA$\mu$ST}
-\title{Getting Started with the FA$\mu$ST Toolbox version 2.1 \smallbreak "Flexible Approximate Multi-Layer Sparse Transforms " \bigbreak
+\title{Getting Started with the FA$\mu$ST Toolbox version 2.1 \textbf{[DEPRECATED
+Guide, please rely on faust.inria.fr and https://gitlab.inria.fr/faustgrp/faust for FAµST v3.x.x+]}\smallbreak "Flexible Approximate Multi-Layer Sparse Transforms " \bigbreak
 \bigbreak
 \centerline{\includegraphics[scale=0.1]{images/logo.png}}
 }