Org files are moved from org/config-website to org/config. Symlink img
was changed accordingly.
org/config/index.org is no longer a symlink and was replaced by the
former README.org which is now shorter and more consice.
org/config/header.org was cleaned, no more lines related to LaTeX
exports and no unused macros
An introduction was added with a direct link to the original org file
as well as the .spacemacs.
Extra packages are now presented as a table, with a description of
what they do and why they are here.
Also modified the behavior of org-mode with
org-structure-template-alist.
