Add Microsoft Cascadia Code font?

[yasu]

Hello Guix Development,

Attached is my Guix package submission of Microsoft Cascadia Code
fonts.

This is my very first attempt to make a Guix package contribution and I
did this in less than 30 minutes, copying the package descriptions of
IBM Plex fonts and modifying a few things.   I dont' know what
protocols I may have missed 😅 

Would you please let me know how to proceed from here?

Regards,
Yasu

0001-i.patch
Description: Text Data