Revert "rangement des fichiers"

See merge request !4

This reverts commit 7577a061

the installation script needs bash which is not the default shell in many ubuntu and debian distribution
replaced /bin/sh with /bin/bash

Switched the arguments in the xsection and xsubsection commands

Fixed bug with xsubsection* and subtitle (call to \subsection[subtitle]{title}, which does not exist)

Adds total frame counter to the footer

See merge request !1

The size is too small. I'll wait for the new graphical chart to do the
official release

Signed-off-by: neze <clement@neze.fr>

When using MacOS without gnu-readlink replacing readlink, the previous version
of the install script didn't work. This one should do the trick.

Signed-off-by: w2ak <w2ak@users.noreply.github.com>