[Icon Request] Mathematica #499

   | Icons for mimetypes are too missing, but there are no instruction regarding how to request for mimetype. 

[Desktop Entry]
Version=1.0
Type=Application
Name=Mathematica 11
Comment=Technical Computing System
TryExec=/usr/local/Wolfram/Mathematica/11.3/Executables/Mathematica
Exec=/usr/local/Wolfram/Mathematica/11.3/Executables/Mathematica %F
Categories=GTK;Education;
Icon=wolfram-mathematica
MimeType=application/mathematica;application/x-mathematica;application/vnd.wolfram.nb;application/vnd.wolfram.cdf;application/vnd.wolfram.player;application/vnd.wolfram.mathematica.package;application/vnd.wolfram.wl;x-scheme-handler/wolfram+cloudobject;x-scheme-handler/wolframmathematica+cloudobject;