Add three per-wiki HtmlConfig keys mirroring vimwiki globals:
- custom_wiki2html / custom_wiki2html_args: when set, export shells out
to the external converter via `sh -c` with vimwiki's exact arg order
(<cmd> <force> <syntax> <ext> <out_dir> <in_file> <css> <tpl_path>
<tpl_default> <tpl_ext> <root_path> <args>, `-` for empty optionals)
instead of the built-in renderer.
- base_url: when set, diary RSS item + channel links become
<base_url><diary_rel_path>/<date>.html instead of file:// URIs.
write_page() gains a `force` flag threaded through export_current (false),
export_all (its own flag) and the did_save auto-export path (false).
Tests: write_page_invokes_custom_wiki2html_converter,
write_rss_uses_base_url_for_public_links (html_export.rs), config
round-trip + defaults (index_and_config.rs). Docs: README, doc/nuwiki.txt,
lua config comment, vimwiki-gap.md item ticked.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
gffranco
23aec3e6c7