Deleted 12.temporary_ins/09.invariances-symmetries/10.main/.gitkeep,...

Deleted 12.temporary_ins/09.invariances-symmetries/10.main/.gitkeep, 12.temporary_ins/09.invariances-symmetries/20.overview/.gitkeep, 12.temporary_ins/09.invariances-symmetries/20.overview/cheatsheet.en.md, 12.temporary_ins/09.invariances-symmetries/20.overview/cheatsheet.es.md, 12.temporary_ins/09.invariances-symmetries/20.overview/cheatsheet.fr.md, 12.temporary_ins/09.invariances-symmetries/20.overview/symetry-mirror-direct-indirect_v2_L900.gif, 12.temporary_ins/09.invariances-symmetries/30.beyond/.gitkeep, 12.temporary_ins/09.invariances-symmetries/30.beyond/annex.en.md, 12.temporary_ins/09.invariances-symmetries/30.beyond/annex.es.md, 12.temporary_ins/09.invariances-symmetries/30.beyond/annex.fr.md files