Merge branch 'enable-parskip' into 'master'

Add parskip package

See merge request !13

standard.tex

 \documentclass{article}
 
-\usepackage{tabularx, tikz, amsmath, gensymb, titlepic, graphicx, listings, makecell}
+\usepackage{tabularx, tikz, amsmath, gensymb, titlepic, graphicx, listings, makecell, parskip}
 \usepackage[margin=1in]{geometry}
 
 \usetikzlibrary{shapes,arrows,fit}