use straight.el for package management

lisp/oxa/package-mgmt.el

@@ -0,0 +1,15 @@
+;; straight.el bootstrap
+(defvar bootstrap-version)
+(let ((bootstrap-file
+       (expand-file-name "straight/repos/straight.el/bootstrap.el" user-emacs-directory))
+      (bootstrap-version 6))
+  (unless (file-exists-p bootstrap-file)
+    (with-current-buffer
+        (url-retrieve-synchronously
+         "https://raw.githubusercontent.com/radian-software/straight.el/develop/install.el"
+         'silent 'inhibit-cookies)
+      (goto-char (point-max))
+      (eval-print-last-sexp)))
+  (load bootstrap-file nil 'nomessage))
+
+(provide 'oxa/package-mgmt)