Fix guides for 8.0

Which dropped support for Ruby 3.1

Author: skipkayhil

Diff for: README.md

@@ -4,6 +4,8 @@
 
 * RVM
 
+* `rvm install 3.2.5`
+
 * `rvm install 3.1.4`
 
 * `rvm install 2.7.6`
@@ -20,6 +22,8 @@
 
 * `rvm use 3.1.4 do gem install bundler --no-doc`
 
+* `rvm use 3.2.5 do gem install bundler --no-doc`
+
 * `kindlegen` must be in `PATH` ([download](http://www.amazon.com/gp/feature.html?docId=1000765211)))
 
 * Install imagemagick, for `convert`, used by the guides generator

Diff for: lib/generators/config/main.rb

@@ -2,7 +2,7 @@ module Generators
   module Config
     module Main
       def ruby_version
-        '3.1.4'
+        '3.2.5'
       end
 
       def api_output

Diff for: lib/generators/config/release.rb

@@ -11,8 +11,10 @@ def ruby_version
           '2.5.3'
         elsif version_number < '7.2.0'
           '2.7.6'
-        else
+        elsif version_number < '8.0'
           '3.1.4'
+        else
+          '3.2.5'
         end
       end