(BREAKING) Don't host-namespace local files

Local cache and data files were stored in a parent folder named after
your host, because I'd symlink the same config across computers via
dropbox. This would cause byte-compile issues in packages, so I stopped
doing this.

Now that each computer gets its own clone, host-namespaced local
directories are unnecessary. There's no other benefit to having them.

core/core-packages.el

@@ -140,7 +140,7 @@ startup."
     (setq load-path doom--base-load-path
           package-activated-list nil)
     ;; Ensure core folders exist
-    (dolist (dir (list doom-local-dir doom-etc-dir doom-cache-dir package-user-dir))
+    (dolist (dir (list doom-local-dir doom-etc-dir doom-cache-dir doom-packages-dir))
       (unless (file-directory-p dir)
         (make-directory dir t)))
     (condition-case _ (package-initialize t)