doc: add module namespace object links

doc/api/modules.md

@@ -209,7 +209,7 @@ regarding which files are parsed as ECMAScript modules.
      `"type": "commonjs"`, and the module contains ES module syntax.
 
 If the ES Module being loaded meets the requirements, `require()` can load it and
-return the module namespace object. In this case it is similar to dynamic
+return the [module namespace object][]. In this case it is similar to dynamic
 `import()` but is run synchronously and returns the name space object
 directly.
 
@@ -254,7 +254,7 @@ by tools converting ES modules into CommonJS modules, following existing ecosyst
 conventions. Code authored directly in CommonJS should avoid depending on it.
 
 When an ES Module contains both named exports and a default export, the result returned by `require()`
-is the module namespace object, which places the default export in the `.default` property, similar to
+is the [module namespace object][], which places the default export in the `.default` property, similar to
 the results returned by `import()`.
 To customize what should be returned by `require(esm)` directly, the ES Module can export the
 desired value using the string name `"module.exports"`.
@@ -1301,6 +1301,7 @@ This section was moved to
 [`process.features.require_module`]: process.md#processfeaturesrequire_module
 [`require.main`]: #requiremain
 [exports shortcut]: #exports-shortcut
+[module namespace object]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/import#module_namespace_object
 [module resolution]: #all-together
 [native addons]: addons.md
 [subpath exports]: packages.md#subpath-exports