Adding propertylib and meshplotlib

.gitignore

docs/conf.py

.../examples/howto_meshplotlib/example_2D_displacement_0.png

.../examples/howto_meshplotlib/example_2D_displacement_1.png

...amples/howto_meshplotlib/example_2D_hydraulics_domain.png

docs/examples/howto_meshplotlib/example_2D_material_id.png

docs/examples/howto_meshplotlib/example_2D_temperature.png

docs/examples/howto_meshplotlib/example_2D_velocity.png

docs/examples/howto_meshplotlib/example_3D_1x3.png

docs/examples/howto_meshplotlib/example_3D_2x2.png

docs/examples/howto_meshplotlib/example_3D_diagonal.png

docs/examples/howto_meshplotlib/example_3D_isometric.png

docs/examples/howto_meshplotlib/index.md

docs/examples/index.md

docs/releases/ogstools-0.0.3.md

docs/user-guide/index.md

docs/user-guide/meshplotlib.md

docs/user-guide/propertylib.md

ogstools/meshplotlib/README.md

ogstools/meshplotlib/TODO