docs: indicate 'exports' interface does not work in browsers

docs/API.md

@@ -10,6 +10,10 @@ Congratulations! You've found Mocha's API documentation. These docs are for deve
 
 Otherwise, **you probably want the [main documentation](https://mochajs.org)**.
 
+## Exports Interface
+
+The "exports" interface is useful for organizing tests in a modular fashion. However, please note that the "exports" interface is **not supported in browser environments**. This is due to the way browsers handle module exports, which differs from Node.js. If you need to organize your tests for a large OOP project, consider using the BDD or TDD interfaces instead.
+
 ## Other Links
 
 - **[Main Documentation](https://mochajs.org)**

docs/index.md

@@ -46,6 +46,10 @@ Mocha is a feature-rich JavaScript test framework running on [Node.js][] and in
 - [TextMate bundle](#textmate)
   {:.two-column}
 
+## Running Mocha
+
+Mocha can be run in various environments, including Node.js and browsers. While most interfaces such as BDD and TDD are fully supported, please note that the "exports" interface does not work in browser environments due to how browsers handle module exports. Refer to the [Interfaces](./API.md#exports-interface) and [Browser Support](./browser-support.md) documentation for more details.
+
 ## Table of Contents
 
 {{ toc }}