markdown: further HTML blocks improvement

[exkrexpexfex]

Fixes nightroman/FarNet#71 new observations reported by @johnd0e

[nightroman]

Some close-tags became open-tags. This does not change colors but look like a bug.
E.g. in

<div class="MyClass">
    <p>Inline HTML, not code</p>
</div>

</p> is now Region: html:htmlOpenTag (use F11 / FarColorer / Region info to see this).

[exkrexpexfex]

htmlOpenTag and htmlCloseTag are the same in html.hrc and across all the base, so it makes no difference.

[johnd0e]

htmlOpenTag and htmlCloseTag are the same in html.hrc and across all the base, so it makes no difference.

Sure they are related, and there can be no functional difference, but..
The are still semantically different entities, and it would be nice to be able to distinguish between them, e.g. for debugging purposes.

[johnd0e]

What I've found.

README.md

<div align="center">

<img width="1232" height="693" alt="witr_banner" src="https://github.com/user-attachments/assets/e9c19ef0-1391-4a5f-a015-f4003d3697a9" />

</div>

• 1st screenshot: it's unclear why the space is colored (that does not happen in plain html). But not an issue of cause.
• 2nd screenshot: the whole content of the tag is colored. That brings too much focus on the whole line. Though acceptable, I would prefer to avoid that. Is it fixable?

[johnd0e]

Under the new schema, tags are now italicized (they weren't before), but colored tags are not.
This inconsistency causes noticeable visual flicker when moving the cursor.
I would prefer the italicization of tags to remain constant, regardless of whether they are colored.

[exkrexpexfex]

@johnd0e so we have to abandon pair match for HTML Blocks 6 and 7. Anyway we have abandoned it within the contents by the previous commit, so the inner tags are not paired anymore. Also the end of blocks 6 and 7 matching starting block is the empty line as per the specs, which cant be highlighted by colorer unless it contains whitespaces. So trying to highlight block start for these brings more confusion than benefit.
I've kept pair matching only for HTML Block type 1, as the contents is still parsed by original HTML scheme with open-closing tags matching.

Please check new version, I force pushed to keep the tree clean.

[johnd0e]

LGTM
So tag name in italics is by design?

[exkrexpexfex]

LGTM So tag name in italics is by design?

Depends on your HRD and font, I guess. By default seems not. From the repo root
./bin/colorer -c ./base/catalog.base.xml -h ./tests/test/other/markdown.md >test.html
gives
test.html

[nightroman]

Looks good to me, @ctapmex please merge when you have some time. Thank you, everybody!