ROADMAP: remove completed entries, mention websocket

docs/ROADMAP.md

@@ -10,21 +10,8 @@ Roadmap of things Daniel Stenberg wants to work on next. It is intended to
 serve as a guideline for others for information, feedback and possible
 participation.
 
-## "Complete" the HTTP/3 support
+## WebSocket
 
-curl has experimental support for HTTP/3 since a good while back. There are
-some functionality missing and once the final specs are published we want to
-eventually remove the "experimental" label from this functionality.
+Agree that it is a good enough API and remove the EXPERIMENTAL label.
 
-## HTTPS DNS records
-
-As a DNS version of alt-svc and also a pre-requisite for ECH (see below).
-
-See: https://datatracker.ietf.org/doc/html/draft-ietf-dnsop-svcb-https-02
-
-## ECH (Encrypted Client Hello - formerly known as ESNI)
-
- See Daniel's post on [Support of Encrypted
- SNI](https://curl.se/mail/lib-2019-03/0000.html) on the mailing list.
-
- Initial work exists in [PR 4011](https://github.com/curl/curl/pull/4011)
+##