Add hack to use non-profile paths

This unsets DOOMPROFILE from inside the profile loader, which should
result in Doom behaving as if we were not using profiles at all.

I'm marking this experimental in part because it feels like a hack, and
in part because this is not sufficient to fix `doom doctor`.

README.md

@@ -143,6 +143,10 @@ source.
 
   When migrating from "normal" Doom, you may need to move some files around.
 
+  If this bothers you, you can try setting `noProfileHack = true`. This makes
+  Unstraightened use the usual paths (relative to `doomLocalDir`), but is
+  experimental.
+
 ## Comparison to `nix-doom-emacs`
 
 - Unstraightened does not attempt to use straight.el at all. Instead, it uses