🚑 (index): replace DM icon with the icon from Discord's CDN

The website of DM is currently down :-(
3 jobs for master in 1 minute and 53 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #5300
lint

00:01:00

 
  Deploy
passed #5301
pages

00:00:53

passed pages:deploy

00:00:00