Describe your feature request

The (new GUI) font family settings should allow custom fonts and not only the 4 hard coded ones. Even the settings file on disk cannot be changed due settings validation (JSON schema) without patching Mark Text source code. This also applies for code block fonts.

What problem does this feature solve? [optional]

This feature/regression should add custom font families to Mark Text back because not everyone want's to use the hard coded ones or can use these fonts. E.g. on Linux only Open Sans or sans-serif are available because the others are proprietary fonts and cannot be used.

Versions

• Mark Text: v0.14.0 develop build / upcoming v0.15.0
• Operating system: all