[Pillar] Free beginners guide to Latex

Pillar is the official documentation system of Pharo. It uses syntax similar to markdown which make it simple and easy to learn. However Pillars power and flexibility goes far beyond that because it leverages Latex , epecially for generating PDFs ( every PDF you have seen read for Pharo uses Latex and Pillar, except a few that use only Latex) or using advanced features like math notations , more precise image locations etc.