[ruby/set] Improve What's Here links

https://github.com/ruby/set/commit/76b056c3b9

lib/set.rb

@@ -66,8 +66,8 @@
 #
 #  First, what's elsewhere. \Class \Set:
 #
-# - Inherits from {class Object}[Object.html#class-Object-label-What-27s+Here].
-# - Includes {module Enumerable}[Enumerable.html#module-Enumerable-label-What-27s+Here],
+# - Inherits from {class Object}[https://docs.ruby-lang.org/en/master/Object.html#class-Object-label-What-27s+Here].
+# - Includes {module Enumerable}[https://docs.ruby-lang.org/en/master/Enumerable.html#module-Enumerable-label-What-27s+Here],
 #   which provides dozens of additional methods.
 #
 # In particular, class \Set does not have many methods of its own