feat: add various system and theme icons, configuration files, and support assets

squashfs-root/usr/share/X11/xkb/symbols/parens

@@ -0,0 +1,8 @@
+// swap parentheses and square brackets
+default partial
+xkb_symbols "swap_brackets" {
+    replace key <AE09> {        [         9,    bracketleft     ]       };
+    replace key <AE10> {        [         0,    bracketright    ]       };
+    replace key <AD11> {        [ parenleft,    braceleft       ]       };
+    replace key <AD12> {        [ parenright,   braceright      ]       };
+};