clint

The screenshot on that page does have the add to path option checked and also says "When you get to the screen below, make sure to check the “Add Ruby...

Looks like kramdown:syntax_highlighter takes the value of highlighter now starting in Jekyll 3.2.1 (in this commit: https://github.com/jekyll/jekyll/commit/9d1641f163e6b20507436872336414cf6df931c7). Also https://pages.github.com/versions/ lists rouge 1.11.1.

"previously opened command line windows need to be closed beforehand". Yes, previously opened command line instances will not pick up the new PATH value. You have to close and open...

This is a 64-bit specific issue with the DevKit. #53 fixes this in bcf23f3 by documenting the workarounds.

I can also confirm lankymart's comment that the Ruby for Windows installer includes RubyGems.