Select better monospace font

[ccordoba12]

Now that we have our installers, it's easier for us to control how things look in them. One thing I'd like to do for Spyder 5 is to select a better monospace font.

Here are some great free fonts we could use for that:

https://devfonts.gafi.dev/

[juanis2112]

We could use https://fonts.google.com/specimen/Inconsolata since that is the one we chose for the docs.