1. Addition of *Running Jekyll on Ubuntu* section, to address Ubuntu stumbling block as per https://github.com/jekyll/jekyll/issues/5719.
2. Restructuring, and I hope I understood correctly when NodeJS/Python are/aren't required.
3. Gentler wording – it's probably not a good idea to tell punters who hit this page because they ran into trouble that installing Jekyll *is* easy and straight-forward; it *ought to be* straight-forward. (There's always the potential for pain and confusion if not all dependencies are in place.)
It turns out Liquid throws an error when you write `{% if {{ include.url }} %}` instead of `{% if {{include.url}} %}`. I updated the examples here to omit the spacing. To avoid inconsistency, I just omitted the spacing from all curly braces. Also added a note explaining the issue and put the blame on Liquid.
- made updates from Parkr's review
- update to Extensionless permalinks section
- update to note about not using built-in perm styles in front matter
- update for readability in places
I added a documentation page on how to build navigation for your site. This topic is primarily intended for users who have a lot of pages on their site (such as for documentation websites), and want to build a more robust sidebar navigation.
Jekyll combines Liquid with YAML in interesting ways that aren't really documented clearly in the existing docs, except for a brief reference [here](http://jekyllrb.com/docs/datafiles/#the-data-folder). You can read about Liquid on Shopify and YAML in YAML's docs, but exactly how you store YAML files in a Jekyll project and iterate through them using Liquid loops and filters to generate lists of pages is something that isn't clear to a lot of people. (You can see origins of these questions in [previous help issues](https://github.com/jekyll/jekyll-help/issues/266).) The documentation on navigation would fit well into the Jekyll docs.
