Add Pi sample #2492

Job	Run time
codespell	20s
copyright_check	7s
examples_clang-format	7s
examples_ubuntu-latest_g++_cxx14_relwithdebinfo_preview=OFF	4m 7s
examples_macos-12_clang++_cxx14_relwithdebinfo_preview=ON	5m 50s
examples_ubuntu-20.04_g++_cxx17_release_preview=ON	4m 52s
examples_ubuntu-20.04_g++-10_cxx20_debug_preview=ON	5m 22s
ubuntu-latest_g++_cxx14_relwithdebinfo_preview=OFF	33m 10s
macos-12_clang++_cxx14_relwithdebinfo_preview=ON	23m 49s
ubuntu-20.04_g++_cxx17_release_preview=ON	22m 1s
python_module_test_ubuntu_latest	44s
ubuntu-20.04_g++-10_cxx20_debug_preview=ON	18m 38s
examples_windows_cl2019_cxx14_relwithdebinfo_preview=ON	6m 32s
examples_windows_cl2022_cxx17_relwithdebinfo_preview=OFF	8m 6s
windows_cl2019_cxx14_relwithdebinfo_preview=ON	26m 18s
windows_cl2022_cxx17_relwithdebinfo_preview=OFF	22m 27s
documentation	1m 28s
pages	0s
	3h 3m 58s

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