Docs: move IRC channel from Freenode to Libera.Chat

Resolves #1643.

README.md

@@ -160,8 +160,8 @@ Support
   [the mailing list](https://groups.google.com/group/newsboat)
   (newsboat@googlegroups.com)
 * Chat with developers and fellow users on #newsboat at
-  [Freenode](https://freenode.net) ([webchat
-  available!](https://webchat.freenode.net/?channels=newsboat))
+  [irc.libera.chat](https://libera.chat). We *do not* have a channel on
+  Freenode anymore.
 
 Contributing
 ------------

doc/internal/howto-release.md

@@ -118,7 +118,7 @@ branch off the latest release and backport the bugfixes onto it.
     * Push the code: `git push && git push --tags`
 8. Tell the world about it:
     * Send an email to the mailing list
-    * Change the topic on #newsboat at Freenode
+    * Change the topic on #newsboat at irc.libera.chat
 9. Release the snap:
     * For minor releases:
         * Go to https://dashboard.snapcraft.io/ and log in.

doc/newsboat.asciidoc

@@ -1613,9 +1613,9 @@ Non-security issues and general questions can be discussed on
 https://github.com/newsboat/newsboat/issues/[the issue tracker] and
 mailto:newsboat@googlegroups.com[the mailing list].
 
-You can also chat with developers and fellow users on #newsboat at Freenode
-(irc.freenode.net or https://webchat.freenode.net/?channels=newsboat[via
-webchat]).
+You can also chat with developers and fellow users on #newsboat at
+https://libera.chat/[irc.libera.chat]. We _do not_ have a channel on Freenode
+anymore.
 
 [appendix]
 == Newsboat Configuration Commands

newsboat.cpp

@@ -145,7 +145,7 @@ void print_usage(const std::string& argv0, const std::string& config_path,
 	print_filepath(tr_cache, cache_path);
 
 	std::cout << std::endl
-		<< _("Support at #newsboat at https://freenode.net or on our mailing "
+		<< _("Support at #newsboat at https://libera.chat or on our mailing "
 			"list https://groups.google.com/g/newsboat")
 		<< std::endl
 		<< _("For more information, check out https://newsboat.org/")

src/pbcontroller.cpp

@@ -371,7 +371,7 @@ void PbController::print_usage(const char* argv0)
 	}
 
 	std::cout << std::endl
-		<< _("Support at #newsboat at https://freenode.net or on our mailing "
+		<< _("Support at #newsboat at https://libera.chat or on our mailing "
 			"list https://groups.google.com/g/newsboat")
 		<< std::endl
 		<< _("For more information, check out https://newsboat.org/")