feat(admin): Improve DX for deploying admin externally (#3418)

* init deploy command

* add include flag

* add 'shortcut' flag

* add dev command, fix var replacement, change default behaviour

* cleanup params of build command

* fix defaults when using the plugin to serve admin

* add changeset

* fix globals

* update README

* throw error on no build found

---------

Co-authored-by: Oliver Windall Juhl <59018053+olivermrbl@users.noreply.github.com>

.changeset/mean-ligers-fry.md

@@ -0,0 +1,6 @@
+---
+"@medusajs/admin-ui": patch
+"@medusajs/admin": patch
+---
+
+feat(admin,admin-ui): Updates the default behaviour of the plugin, and makes building for external deployment easier