Example of a plate with a hole

[kks32]

Create a MPM example for a plate with a hole.

• For #10: Try the C++ MPM code https://github.com/cb-geo/mpm to run the 2D example of a plate with a hole https://github.com/cb-geo/mpm-benchmarks/tree/develop/2d/plate_with_hole/cartesian . Then plot the results in paraview.

• Follow this example here: https://github.com/cb-geo/mpm-benchmarks/tree/develop/2d/plate_with_hole/cartesian generate the appropriate input files for diff-mpm Similar to https://github.com/geoelements/diff-mpm/tree/main/examples

• Plot and compare results between CB-Geo MPM and DiffMPM results