README: move from freenode to libera.chat.

README.md

@@ -36,9 +36,10 @@ Here is the final diagram for [step A](process/guide.md#stepA):
 
 If you are interested in creating a mal implementation (or just
 interested in using mal for something), please drop by the #mal
-channel on freenode. In addition to the [make-a-lisp process
-guide](process/guide.md) there is also a [mal/make-a-lisp
-FAQ](docs/FAQ.md) where I attempt to answer some common questions.
+channel on [libera.chat](https://libera.chat/). In addition to the
+[make-a-lisp process guide](process/guide.md) there is also
+a [mal/make-a-lisp FAQ](docs/FAQ.md) where I attempt to answer some
+common questions.
 
 
 **3. Mal is implemented in 86 languages (90 different implementations and 112 runtime modes)**