With the new native JS module system, we have a lot of new features for
the developer: autocompletion, docstrings, ...

However, it does not work across modules: if a JS file in
/addons/stock/static/src/some_file.js want to import a file in web, say
/addons/web/static/src/blabla.js, we will need to use a statement like
this:

import { something } from '@web/blabla';

Obviously, there is no automatic way for IDEs to know that '@web' should
map to 'addons/web'.

This is why we propose to use a tsconfig.json that defines the mapping
between modules and their paths.  This is not mandatory, and only
affects those developers that work commonly in JS.

Part of PR 63177

Co-authored-by: Francois (fge) <fge@odoo.com>