upgrade to Awestruct 0.5.4, fix post template
resolves #105 update user manual section about ToC

- added toc-position
- added code examples for each attribute
- updated appendix A with ToC changes
- added images of example results
- removed manual value
- added left and right values
- unset figure-caption in header
Merge pull request #113 from graphitefriction/toc-syntax-update

resolves #105 update user manual section about ToC
Introducing the Asciidoctor browser live preview
resolves #115 updated table styles

- monospaced first column
- centered second, third and fourth and replaced X with checkmark
- cleaned up some comments in fifth column
Merge pull request #116 from graphitefriction/appendix-style-upgrade

resolves #115 updated table styles
Merge pull request #114

Introducing Asciidoctor.js live preview blog post
update post title, date and tags attribute; minor revisions
fix missing callouts in user manual
use xml-friendly callout
Set publish date of post news/introducing-asciidoctor-js-live-preview.adoc [ci skip]