CI3 User Guide Style

The style of the new guide is clean and professional, and the text is certainly easy to read, even on an iPad. Personally, I find the new sidebar navigation to be an enormous improvement over the old drop-down one which used to get in the way a lot, specially when accessing the docs on mobile devices.

A couple of notes on the CONTENT:
1) Instructions for getting rid of the 'index.php' file in the URIs should perhaps be part of the installation guide - this is something the vast majority of users will want to do.

2) In the 'Static Pages' part of the tutorial, you talk about using a $title variable in the header template, but the template code you get the user to type has no $title in it. At least, on the iPad it doesn't show.

3) In the 'Create News' section of the tutorial, there seems to be a fairly glaring omission: showing the user how to specify that SLUGS should be UNIQUE, and how to handle the case of when they're not. If the topic is considered too advanced for an introductory tutorial - which is likely the case - then perhaps there should be a link to another section of the docs that explains how uniqueness should be checked during form submissions.