All the stand-alone pages from Ruby's doc directory seem to be missing on https://rubyapi.org/3.2/, e.g.:

• encodings.rdoc
• globals.rdoc
• keywords.rdoc
• syntax/assignment.rdoc
• syntax/calling_methods.rdoc
• syntax/methods.rdoc
• syntax/modules_and_classes.rdoc
• ...

In addition, there should be a way to easily discover / browse these pages. In Dash, they can be found under a separate "Guides" section.