Set Font Size in Linux with 4k screen

[nks1974]

Description

RattleNG interface has small font on high resolution screens in Linux (Plasma KDE)

Why

User cannot find a way to increase the RattleNG interface font size in settings.

User has to add
export GDK_DPI_SCALE=2
export GDK_SCALE=2
to his .bashrc file to increase font size.

Closing Crieria

Add font size option or instruction in Settings in interface.

Alternatives

Add font size instruction to readme and note in settings.

Additional Context

[gjwgit]

Thanks for the suggestion.

Marking this as an enhancement to be reviewed and options considered, probably by adding a scale to SETTINGS.

Use of GDK_DPI_SCALE=2 GDK_SCALE=2 rattle for example should be documented.

Need to review how we can manage font sizes/scaling within the app.