Update content/en/docs/a-warm-welcome-to-asn1-and-der.md
Update content/en/docs/a-warm-welcome-to-asn1-and-der.md

Co-Authored-By: Jeremy Barton <ef88cdf223e82d966d05894857ed10061f9c24e7@microsoft.com>
letsencrypt/website,letsencrypt/website,letsencrypt/website