Update README.md

README.md

@@ -81,6 +81,8 @@ Read the [Getting started page](https://v5.getbootstrap.com/docs/5.0/getting-sta
 
 Within the download you'll find the following directories and files, logically grouping common assets and providing both compiled and minified variations. You'll see something like this:
 
+<details><summary>File Contents</summary>
+
 ```text
 bootstrap/
 ├── css/
@@ -131,6 +133,8 @@ bootstrap/
     └── bootstrap.min.js.map
 ```
 
+</details>
+
 We provide compiled CSS and JS (`bootstrap.*`), as well as compiled and minified CSS and JS (`bootstrap.min.*`). [source maps](https://developers.google.com/web/tools/chrome-devtools/javascript/source-maps) (`bootstrap.*.map`) are available for use with certain browsers' developer tools. Bundled JS files (`bootstrap.bundle.js` and minified `bootstrap.bundle.min.js`) include [Popper](https://popper.js.org/).