moved palletes and templates into categories in extra

extra/templates/desktop/gtk/readme.md

@@ -0,0 +1,15 @@
+# GTK
+
+1. Download the [template file](gtk.css)
+
+2. Configure the template in `~/.config/clrsync/config.toml`:
+
+```toml
+[templates.gtk]
+enabled = true
+input_path = '~/.config/clrsync/templates/gtk.css'
+output_path = '~/.config/gtk-3.0/gtk.css'
+reload_cmd = ''
+```
+
+3. Restart GTK applications to apply the theme