resolves #150 always generate ID for section created from non-page entry in nav

resolves #151 use ID prefix to avoid conflict with reserved IDs

resolves #152 when component version is versioned, assign display version to revnumber attribute in assembly

resolves #152 when component version is versioned, assign display version to revnumber attribute in assembly

resolves #145 add @antora/html-single-extension package to assemble and export content to standalone HTML

resolves #145 add @antora/html-single-extension package to assemble and export content to standalone HTML

resolves #149 allow multiple configuration files to be specified per registered extension

resolves #17 remove named id attributes when rewriting block IDs