Markup: rendering edits for 2025 edition & beyond

[gesa]

This PR

• Cleans up and improves comments on ECMA-262-specific print styles
• Restores the (mandatory? i thought?) version line to metadata
• Transforms 5 identical cells into one cell with rowspan 5 in table "Module fields after the initial Evaluate() call"
  • we made this change last year as well, I must have failed to push those changes back to main
• Clarifies in the colophon that ecmarkup is used for Ecma specifications, not just ECMAScript specifications

[nicolo-ribaudo]

• Transforms 5 identical cells into one cell with rowspan 5 in table "Module fields after the initial Evaluate() call"
  • we made this change last year as well, I must have failed to push those changes back to main

I'm going to complain just a little bit because I should have complained last year, but I don't really like it. They are 5 cells that happen to have the same value, not just a single cell.

[gesa]

@nicolo-ribaudo That's totally legit. I think it's important to keep in the printable version (it's the only way all the text fits on the page) but I do not feel strongly—at all—about adding it to the web version, aka the actual source of truth.