Do not render inline :doc: modifiers in method descriptions

[skatkov]

Summary

The :doc: modifier forces a method to be documented, but the inline modifier text currently leaks into the rendered markdown description.

Reference

RDoc Markup reference: https://www.mikeperham.com/wp-content/uploads/2010/12/rdoc.html

Example source

class DirectiveProbe
  # hidden helper # :doc:
  def helper; end
end

Current markdown output

#### `helper()`

hidden helper # :doc:

Expected behavior

The method should be documented because of :doc:, but the rendered description should not include the modifier text.

#### `helper()`

hidden helper

[skatkov]

RDoc master comparison note: still reproduces.

Tested with ruby/rdoc master at bc0baee787609f2205e8f1103f3e1d36b923184a. A minimal # hidden helper # :doc: probe still renders hidden helper # :doc: in the method description.

Related upstream directive work, but no exact upstream duplicate found:

• Lexical scope document control directives ruby/rdoc#1591
• Accept misused :nodoc: usage ruby/rdoc#1578