Modernize references to other software (#3937)

* Mention that only some Node.js versions require experimental-modules flag
* Change webpack 2 to just webpack since 3,4 and 5 also support ESM

README.md

@@ -65,7 +65,7 @@ rollup main.js --format umd --name "myBundle" --file bundle.js
 
 Developing software is usually easier if you break your project into smaller separate pieces, since that often removes unexpected interactions and dramatically reduces the complexity of the problems you'll need to solve, and simply writing smaller projects in the first place [isn't necessarily the answer](https://medium.com/@Rich_Harris/small-modules-it-s-not-quite-that-simple-3ca532d65de4). Unfortunately, JavaScript has not historically included this capability as a core feature in the language.
 
-This finally changed with ES modules support in JavaScript, which provides a syntax for importing and exporting functions and data so they can be shared between separate scripts. The specification is now implemented in all major browsers and in Node.js behind the --experimental-modules flag for ".mjs" files. Rollup allows you to write your code using this module system, either outputting optimized ES modules for use in these native environments, or compiling it back down to existing supported formats such as CommonJS modules, AMD modules, and IIFE-style scripts. This means that you get to *write future-proof code*, and you also get the tremendous benefits of...
+This finally changed with ES modules support in JavaScript, which provides a syntax for importing and exporting functions and data so they can be shared between separate scripts. Most browsers and Node.js support ES modules. However, Node.js releases before 12.17 support ES modules only behind the `--experimental-modules` flag, and older browsers like Internet Explorer do not support ES modules at all. Rollup allows you to write your code using ES modules, and run your application even in environments that do not support ES modules natively. For environments that support them, Rollup can output optimized ES modules; for environments that don't, Rollup can compile your code to other formats such as CommonJS modules, AMD modules, and IIFE-style scripts. This means that you get to *write future-proof code*, and you also get the tremendous benefits of...
 
 ## Tree Shaking
 
@@ -101,7 +101,7 @@ Rollup can import existing CommonJS modules [through a plugin](https://github.co
 
 ### Publishing ES Modules
 
-To make sure your ES modules are immediately usable by tools that work with CommonJS such as Node.js and webpack, you can use Rollup to compile to UMD or CommonJS format, and then point to that compiled version with the `main` property in your `package.json` file. If your `package.json` file also has a `module` field, ES-module-aware tools like Rollup and [webpack 2](https://webpack.js.org/) will [import the ES module version](https://github.com/rollup/rollup/wiki/pkg.module) directly.
+To make sure your ES modules are immediately usable by tools that work with CommonJS such as Node.js and webpack, you can use Rollup to compile to UMD or CommonJS format, and then point to that compiled version with the `main` property in your `package.json` file. If your `package.json` file also has a `module` field, ES-module-aware tools like Rollup and [webpack](https://webpack.js.org/) will [import the ES module version](https://github.com/rollup/rollup/wiki/pkg.module) directly.
 
 ## Contributors