Provide missing theoretical comments for notebooks

[AgnieszkaZaba]

List of notebooks that do not have description:

• Arabas_et_al_2023/copula_hello.ipynb
• Arabas_et_al_2023/figs_10_and_11_animations.ipynb
• Arabas_et_al_2015/paraview_hello_world.ipynb
• Arabas_et_al_2023/fig_2.ipynb
• Bartman_et_al_2021/demo_fig2.ipynb
• Bartman_et_al_2021/demo.ipynb
• Bartman_et_al_2021/demo_fig3.ipynb
• Bulenok_2023_MasterThesis/performance_comparison_Srivastava_Setup
• deJong_Azimi/box.ipynb
• deJong_Mackay_et_al_2023/figs_3_4_5.ipynb
• seeding/seeding_no_collisions.ipynb
• Srivastava_1982/figures.ipynb