transplant course from https://forge.ird.fr/mivegec/dainat/malbec-unix-basics and few updates

.gitignore

LICENCE.txt

README.md

conda_env.yml

docs/figures.pptx

docs/index.md

docs/pages/bash/bash-0-setup.md

docs/pages/bash/bash-1-introduction.md

docs/pages/bash/bash-2-the-basics.md

docs/pages/bash/bash-3-navigating.md

docs/pages/bash/bash-4-working_with_files_and_directories.md

docs/pages/bash/bash-5-special_characters.md

docs/pages/bash/bash-6-path.md

docs/pages/bash/bash-7-commands.md

docs/pages/bash/bash-8-loops.md

docs/pages/bash/bash-9-scripting.md

docs/pages/cheat_sheet/bash/Bash_cheat_sheet_level1.pdf

docs/pages/cheat_sheet/bash/Bash_cheat_sheet_level2.pdf

docs/pages/cheat_sheet/bash/Bash_cheat_sheet_level3.pdf

docs/pages/cheat_sheet/bash/bash.md