examples: Add a notebook demonstrating curvilinear FD #6794

Job	Run time
pytest-ubuntu-py311-gcc11-noomp-base	37m 56s
pytest-ubuntu-py311-gcc11-noomp-adjoint	34m 5s
pytest-ubuntu-py38-gcc12-omp-base	40m 31s
pytest-ubuntu-py38-gcc12-omp-adjoint	34m 16s
pytest-ubuntu-py38-gcc7-omp-base	40m 30s
pytest-ubuntu-py38-gcc7-omp-adjoint	34m 28s
pytest-ubuntu-py310-gcc10-noomp-base	37m 59s
pytest-ubuntu-py310-gcc10-noomp-adjoint	32m 9s
pytest-ubuntu-py312-gcc13-omp-base	49m 37s
pytest-ubuntu-py312-gcc13-omp-adjoint	42m 0s
pytest-ubuntu-py39-gcc9-omp-base	39m 16s
pytest-ubuntu-py39-gcc9-omp-adjoint	33m 30s
pytest-osx-py312-clang-omp-base	1m 39s
pytest-docker-py39-gcc-omp-base	38m 52s
pytest-docker-py39-gcc-omp-adjoint	29m 37s
pytest-docker-py39-icx-omp-base	31m 56s
pytest-docker-py39-icx-omp-adjoint	29m 22s
	9h 47m 43s

Provide feedback