Update README to include Rails 8.x

Author: JonathanTron

README.md

@@ -9,7 +9,7 @@
 
 This gem provides the railtie that allows
 [sequel](http://github.com/jeremyevans/sequel) to hook into
-[Rails (5.2.x, 6.x, 7.x)](http://github.com/rails/rails) and thus behave like a
+[Rails (5.2.x, 6.x, 7.x, 8.x)](http://github.com/rails/rails) and thus behave like a
 rails framework component. Just like activerecord does in rails,
 [sequel-rails](http://github.com/talentbox/sequel-rails) uses the railtie API to
 hook into rails. The two are actually hooked into rails almost identically.
@@ -27,7 +27,7 @@ Since January 2013, we've become the official maintainers of the gem after
 Using sequel-rails
 ==================
 
-Using sequel with Rails (5.2.x, 6.x, 7.x) requires a few minor changes.
+Using sequel with Rails (5.2.x, 6.x, 7.x, 8.x) requires a few minor changes.
 
 First, add the following to your Gemfile (after the `Rails` lines):