Log Message:
materia-gtk-theme: Update to 20200320

Changes:

Make dark variant even darker
Don't change button text color on focus, hover, active
gtk: Rewrite ripple implementation
gtk: Change checked raised button style
gtk: Lighten up switch slider color on dark variant
gtk: Use primary color for spinner
gtk: Use primary color for caret-color (experimentally)
gtk: Add various improvements of Budgie styling
gnome-shell: Add support for version 3.36
gnome-shell: Drop support for versions 3.18 - 3.24
gnome-shell: Drop support for legacy Ubuntu-specific sessions
gnome-shell: Land massive Sass rewrite
Other various improvements, fixes, refactors, and cleanups