remove LaTeX-Extended
Squashed 'LaTeX-Extended/' content from commit 236152c

git-subtree-dir: LaTeX-Extended
git-subtree-split: 236152c1ceec1a431f6fa50af48fe5b058fd2c0f
Merge commit '9b1a43b003bdc87422aac24c935ae4ddfdfb114a' as 'LaTeX-Extended'