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/cmp/cmp.nix

@@ -5,7 +5,7 @@
       enable = true;
       settings = {
         autoEnableSources = true;
-        experimental = {ghost_text = true;};
+        experimental = {ghost_text = false;};
         performance = {
           debounce = 60;
           fetchingTimeout = 200;