Add links to config files in describe-packages

Also dims packages that aren't installed.

core/core-lib.el

@@ -222,7 +222,9 @@ BODY is evaluated once TARGETS are loaded. TARGETS can either be:
               #'progn
             #'with-no-warnings)
           (if (symbolp targets)
-              `(with-eval-after-load ',targets ,@body)
+              `(progn
+                 (doom-module-register-config ',targets ,(FILE!))
+                 (with-eval-after-load ',targets ,@body))
             (pcase (car-safe targets)
               ((or :or :any)
                (macroexp-progn