tweak(cli): remove 'doom i' alias

Freeing this up to use for a future command (doom init), and because
'doom install' ought to be used very rarely and deliberately, so it
shouldn't have a convenient alias anyway.

bin/doom

@@ -269,7 +269,7 @@ SEE ALSO:
     (defcli-autoload! ((upgrade up)))
     (defcli-autoload! (env))
     (defcli-autoload! ((build b purge p gc rollback)) "packages")
-    (defcli-autoload! ((install i)))
+    (defcli-autoload! (install))
 
     ;; TODO Post-3.0 commands
     ;; (load! "gc" dir)

lisp/cli/install.el

@@ -14,7 +14,7 @@
 ;;
 ;;; Commands
 
-(defcli! ((install i))
+(defcli! install
     ((aot?     ("--aot") "Enable ahead-of-time native-compilation (if available)")
      &flags
      (config?  ("--config" :yes)  "Create `$DOOMDIR' or dummy files therein?")