Update the README

Author: bbatsov

README.adoc

@@ -19,7 +19,7 @@ Installing the Antora is super simple:
 $ make npm
 ----
 
-Check out https://docs.antora.org/antora/2.0/install/install-antora/[the detailed installation instructions]
+Check out https://docs.antora.org/antora/3.1/install/install-antora/[the detailed installation instructions]
 if you run into any problems.
 
 == Building the Site
@@ -68,9 +68,6 @@ looks for one of the projects:
 
 TIP: You need to add one such block for each new CIDER module you're adding to the docs site.
 
-After releases of CIDER you also need to update the default landing
-version (it should always be the latest version).
-
 == Troubleshooting
 
 The most common mistake that people make is to forget to update the version of an Antora docs module