Arrow missing from home page

[pitrou]

The main page doesn't mention Arrow (well, it does, but only as an example of xsimd-using library).

[HaudinFlorence]

@SylvainCorlay @pitrou We can maybe modify the scientific computing section to better evidence Arrow project maybe in a separate bullet point ? (also adding the logo with the one of XSimd and Xtensor). At the moment it is only C++ librairies displayed in that section (if I am not mistaking) so the title should be changed. Feel free to share suggestions.

[pitrou]

@HaudinFlorence Yes, that's a good idea!