patch: mix fixes (#33)

- During build time multiple warnings were shown about the deprecation
of certain options. These have been moved to their new places.
- Disable the CMP Ghost Text option because it was driving me nuts.

config/plugins/utils/markdown-preview.nix

@@ -4,11 +4,11 @@ _: {
       enable = true;
       settings = {
         browser = "firefox";
-        echo_preview_url = true;
+        echo_preview_url = 1;
         port = "6969";
         preview_options = {
-          disable_filename = true;
-          disable_sync_scroll = true;
+          disable_filename = 1;
+          disable_sync_scroll = 1;
           sync_scroll_type = "middle";
         };
         theme = "dark";