Merge branch 'fix-issue-73' into 'master'

docs.it4i/software/chemistry/files-nwchem/h2o.nw

docs.it4i/software/chemistry/files-phono3py/INCAR.txt

docs.it4i/software/chemistry/files-phono3py/KPOINTS.txt

docs.it4i/software/chemistry/files-phono3py/POSCAR.txt

docs.it4i/software/chemistry/files-phono3py/POTCAR.txt

docs.it4i/software/chemistry/files-phono3py/gofree-cond1.sh

docs.it4i/software/chemistry/files-phono3py/prepare.sh

docs.it4i/software/chemistry/files-phono3py/run.sh

docs.it4i/software/chemistry/files-phono3py/submit.sh

docs.it4i/software/chemistry/files-phonopy/INCAR

docs.it4i/software/chemistry/files-phonopy/KPOINTS

docs.it4i/software/chemistry/files-phonopy/POSCAR

docs.it4i/software/chemistry/files-phonopy/mesh.conf

docs.it4i/software/chemistry/gaussian.md

docs.it4i/software/chemistry/nwchem.md

docs.it4i/software/chemistry/orca.md

docs.it4i/software/chemistry/phono3py.md

docs.it4i/software/chemistry/phonopy.md

docs.it4i/software/lang/python.md

docs.it4i/software/machine-learning/introduction.md