feat: simplify changing the theme

You can now create a theme in `themes.json` and set the color attribute
to the theme name in `config.json`.

config.json

@@ -16,24 +16,5 @@
     "paypal": "https://paypal.me/cveinnt",
     "patreon": "https://patreon.com/cveinnt"
   },
-  "colors": {
-    "light": {
-      "background": "#FBF1C9",
-      "foreground": "#3C3836",
-      "yellow": "#D79921",
-      "green": "#98971A",
-      "gray": "#7C6F64",
-      "blue": "#458588",
-      "red": "#CA2124"
-    },
-    "dark": {
-      "background": "#2E3440",
-      "foreground": "#E5E9F0",
-      "yellow": "#5E81AC",
-      "green": "#A3BE8C",
-      "gray": "#88C0D0",
-      "blue": "#EBCB8B",
-      "red": "#BF616A"
-    }
-  }
+  "color": "default"
 }

tailwind.config.js

@@ -1,4 +1,7 @@
-const { colors } = require('./config.json');
+const { color } = require('./config.json');
+const theme = require('./themes.json');
+
+let colors = theme[color];
 
 module.exports = {
   content: [