Bug 43401: (follow-up) Note the Makefile.PL coupling in rspack.config.js

- Add a file-level comment reminding that every shipped output.path needs a
  matching 'NONE' target-map entry and cp step in Makefile.PL

Signed-off-by: Paul Derscheid <paul.derscheid@lmscloud.de>
Signed-off-by: David Cook <dcook@prosentient.com.au>
Signed-off-by: Pedro Amorim <pedro.amorim@openfifth.co.uk>

rspack.config.js

@@ -3,6 +3,11 @@ const { VueLoaderPlugin } = require("vue-loader");
 const path = require("path");
 const rspack = require("@rspack/core");
 
+// NOTE: Every output.path under koha-tmpl/ that ships must also be handled in
+// Makefile.PL: the 'NONE' entries in the target-directory map and the cp -r
+// lines in the compile step. A new dist dir added here without both changes is
+// silently omitted from packaged builds (see Bug 43401).
+
 const islandsExport = application => {
     const vueDir =
         application === "intranet"