Prevent excessive sanitization of AsciiDoc ouptut
Problem to solve
AsciiDoc output is sanitized by the same filter as for Markdown, and Banzai::Filter::SanitizationFilter is very strict. This strips much of the AsciiDoc generated mark up need for correct formatting.
Loosening the sanitization rules would likely fix many of the outstanding AsciiDoc formatting problems.
Further details
The Banzai::Filter::SanitizationFilter is currently used by both the Banzai::Pipeline::GfmPipeline and Banzai::Pipeline::AsciiDocPipeline, while it's really written specifically for the HTML output by Banzai::Filter::MarkdownFilter, not Asciidoctor.convert.
Proposal
Implement a separate AsciidocSanitizationFilter, perhaps based on Banzai::Filter::SanitizationFilter, with specific looser rules for Asciidoc.