Add info about fdtd3d benchmark page #81

Job	Run time
Unit test x64 ubuntu 22.04 for parallel grid CXX11=ON	42m 4s
Unit test x64 ubuntu 22.04 for parallel grid CXX11=OFF	47m 27s
Unit test x64 ubuntu 22.04 for clock	2m 46s
Unit test x64 ubuntu 22.04 for layout	37m 43s
Unit test x64 ubuntu 22.04 for grid	2m 42s
Unit test x64 ubuntu 22.04 for internalscheme	23m 39s
Unit test x64 ubuntu 22.04 for dumpers-loaders	4m 33s
Unit test x64 ubuntu 22.04 for coordinate	2m 33s
Unit test x64 ubuntu 22.04 for settings	1m 24s
Unit test x64 ubuntu 22.04 for approximation	2m 25s
Unit test x64 ubuntu 22.04 for complex	30s
	2h 47m 46s

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