Merge pull request #228 from graphitefriction/1-5-docs

adds stem section to user manual
Fix result of "Inline anchors" in asciidoc-syntax-quick-reference
Merge pull request #230 from ge0ffrey/patch-1

Fix result of "Inline anchors" in asciidoc-syntax-quick-reference
resolves #229 fix XML-friendly callout example
Merge pull request #231 from mojavelinux/issue-229

resolves #229 fix XML-friendly callout example
updates syntax highlighting examples

- adds pygments attributes and example snippet
- adds coderay section
- adds coderay attributes
- adds pygments output image
- closes #162
- closes asciidoctor/asciidoctor#637
- documents asciidoctor/asciidoctor#604