Remove minor version from the URL.

So, links for version `x.y.z` will be under the `/x.y/` prefix.

Thus, links to previous minor versions will not be broken when a new
one is released.

Author: ayosec

lib/ffdocs/view/website.rb

@@ -240,7 +240,7 @@ def path_for(obj)
       @website_files[obj_key] ||=
         case obj
         in ::FFDocs::SourceDocs::VersionTag
-          @output.join(InvalidPathName.check!(obj.version))
+          @output.join(InvalidPathName.check!(obj.major))
 
         in ::FFDocs::SourceDocs::Group
           [ obj.component, obj.media_type ].