Increase x-height in default font

In #318 I showed an image of SCP compared to JetBrains Mono and Go Mono to compare the x-heights, with JB Mono on top, SCP in the middle and Go Mono at the bottom:

In that issue, the conclusion was to add a variable font where the user can customize the x-height, which I'm not sure how that works. I would like it if the default font itself could have an increased x-height comparable with JB Mono and Go Mono. Taller x-heights are great for UIs and make text on screens more readable, and that's a reason people love fonts like JB Mono, but I like the style of SCP.

Go Mono has an [x-height of 53% it's body size.](https://go.dev/blog/go-fonts).