Fix minor errors in documentation

docs/doc/cli/cli.md

docs/doc/gui/gui.md

docs/doc/releases/releases.md

qim3d/features/_common_features_methods.py

qim3d/filters/_common_filter_methods.py

qim3d/io/_loading.py

qim3d/io/_saving.py

qim3d/mesh/_common_mesh_methods.py

qim3d/viz/_k3d.py