Change links style in PDF

doc/userdoc.org

@@ -21,6 +21,7 @@
 #+LATEX_HEADER: \usepackage{siunitx}
 #+LATEX_HEADER: \usepackage[table]{xcolor}
 #+LATEX_HEADER: \usepackage{colortbl}
+#+LATEX_HEADER: \hypersetup{linktoc = all, colorlinks = true, linkcolor = blue}
 #+LATEX_COMPILER: pdflatex --shell-escape
 
 #+LATEX_HEADER_EXTRA: \usepackage{amsmath}