add ghostty config and theme

configs/ghostty_g/themes/Obsidian

@@ -0,0 +1,21 @@
+palette = 0=#000000
+palette = 1=#a60001
+palette = 2=#00bb00
+palette = 3=#fecd22
+palette = 4=#3a9bdb
+palette = 5=#bb00bb
+palette = 6=#00bbbb
+palette = 7=#bbbbbb
+palette = 8=#555555
+palette = 9=#ff0003
+palette = 10=#93c863
+palette = 11=#fef874
+palette = 12=#a1d7ff
+palette = 13=#ff55ff
+palette = 14=#55ffff
+palette = 15=#ffffff
+background = 283033
+foreground = cdcdcd
+cursor-color = c0cad0
+selection-background = 3e4c4f
+selection-foreground = dfe1e2