mdBodyToAdoc: translate markdown tables to AsciiDoc when rendering roadmap

Main.mdBodyToAdoc (graphitron-rewrite/roadmap-tool/src/main/java/no/sikt/graphitron/roadmap/Main.java) is a best-effort markdown→AsciiDoc converter used by render-adoc to stage roadmap plan bodies into the documentation site. It currently passes markdown tables (| col | col | header rows separated by a |---|---| line) through verbatim, so the rendered .adoc carries raw pipe rows that Asciidoctor displays as paragraph text with literal pipes rather than a table. R223 added a verify-phase check that flags this pattern in authored .adoc, but explicitly defers the render-side hole; markdown tables embedded in .md roadmap plans still leak into the rendered roadmap site. This item is the follow-up: extend mdBodyToAdoc to detect a markdown-table block (header row + separator + body rows, terminated by a blank line) and emit an AsciiDoc |=== block with a [cols=…​] attribute synthesized from the separator’s column count and any GFM alignment markers.