Add test and improve handling of subpath for man inline macro

lib/asciidoctor/foodogsquared/man-inline-macro/extension.rb

@@ -34,8 +34,9 @@ module Asciidoctor::Foodogsquared::Extensions
                    raise "no available manpage service #{attrs['service']}"
                  end
 
+        subpath = "#{attrs['subpath'].delete_prefix('/').delete_suffix('/')}/" if !attrs['subpath'].empty?
         if !domain.nil?
-          target = %(#{domain}/#{attrs['subpath'].delete_prefix '/'}#{manname}.#{attrs['volnum']})
+          target = %(#{domain}/#{subpath}#{manname}.#{attrs['volnum']})
           doc.register :links, target
           node = create_anchor parent, text, type: :link, target: target
         else

spec/man_inline_macro_spec.rb

@@ -12,6 +12,17 @@ describe ManInlineMacro do
     (expect actual).to include expected.chomp
   end
 
+  it 'should process with the Debian Bookworm section' do
+    input = 'man:ls[1, service=debian, subpath=/bookworm]'
+
+    expected = <<~RESULT
+      <a href="https://manpages.debian.org/bookworm/ls.1">ls(1)</a>
+    RESULT
+
+    actual = (Asciidoctor.convert input).tr_s '\n', '\n'
+    (expect actual).to include expected.chomp
+  end
+
   it 'should link to the Arch Linux manpage' do
     input = 'man:ls[volnum=1, service=arch]'