Older browser support

Author: jfoskin

src/connections/sources/catalog/libraries/website/javascript/supported-browsers.md

@@ -23,6 +23,8 @@ The library is regularly tested and is functional with the following browsers:
 
 Segment guarantees support for Internet Explorer 11 and later for Analytics.js. Remember that different bundled (device-mode) destinations might have different compatibility guarantees for their own products. Refer to the vendor's documentation to confirm browser compatibility.
 
+If you need to support pre-ie11 browsers or old versions of Opera, Segment encourage's you to either load a polyfill script in the head (https://cdnjs.cloudflare.com/ajax/libs/babel-polyfill/7.7.0/polyfill.min.js) or use the analytics-next npm package and bundle/polyfill themselves: for example, https://babeljs.io/docs/babel-preset-env. 
+
 > info ""
 > Classic destinations and Analytics.js support Internet Explorer 11, but some Actions destinations are not yet supported.