add ghostty config and theme

configs/ghostty_g/themes/Mathias

@@ -0,0 +1,21 @@
+palette = 0=#000000
+palette = 1=#e52222
+palette = 2=#a6e32d
+palette = 3=#fc951e
+palette = 4=#c48dff
+palette = 5=#fa2573
+palette = 6=#67d9f0
+palette = 7=#f2f2f2
+palette = 8=#555555
+palette = 9=#ff5555
+palette = 10=#55ff55
+palette = 11=#ffff55
+palette = 12=#5555ff
+palette = 13=#ff55ff
+palette = 14=#55ffff
+palette = 15=#ffffff
+background = 000000
+foreground = bbbbbb
+cursor-color = bbbbbb
+selection-background = 555555
+selection-foreground = f2f2f2