docs: update feature screenshots (#1018)

Floatpane Bot created

Change summary

docs/docs/assets/features/compose_email.png  | 0 
docs/docs/assets/features/main_menu.png      | 0 
docs/docs/assets/features/settings.png       | 0 
docs/docs/assets/features/theme_settings.png | 0 
4 files changed

Detailed changes