Explicitly document existing de facto policy of supporting ESR Firefox

Refs #17237
[skip sauce]

diff --git a/docs/getting-started/browsers-devices.md b/docs/getting-started/browsers-devices.md
index fab9a3fea8435857e1802bf71a1f7b7289a47445..f70938f54e971cb827bd51dece882c9edbe83828 100644 (file)
--- a/docs/getting-started/browsers-devices.md
+++ b/docs/getting-started/browsers-devices.md
@@ -92,6 +92,8 @@ Similarly, the latest versions of most desktop browsers are supported.
   </table>
 </div>
 
+For Firefox, in addition to the latest normal stable release, we also support the latest [Extended Support Release (ESR)](https://www.mozilla.org/en-US/firefox/organizations/faq/) version of Firefox.
+
 Unofficially, Bootstrap should look and behave well enough in Chromium and Chrome for Linux, Firefox for Linux, and Internet Explorer 8 and below, though they are not officially supported.
 
 For a list of some of the browser bugs that Bootstrap has to grapple with, see our [Wall of browser bugs]({{ site.baseurl }}/browser-bugs/).