[Markdown] Prepare Learn docs for Markdowning

[wbamberg]

This is a tracking bug for the work we have to do to prepare the Learn documentation for Markdown conversion.

• remove id attributes except on headings
  • [Markdown] [Learn] Remove non-heading ID attributes #9356
  • [Markdown] [Learn] Fix CSS live samples #9351
• deal with hidden code blocks in live samples:
  • [Markdown] [Learn] Remove hidden divs #9564
• remove hidden elements that don't contain code blocks in a live sample (there are none)
• remove summary and seoSummary class:
  • [Markdown] [Learn] Remove summary class from Learn docs #9401
  • [Markdown] [Learn] Remove summary and seoSummary classes #9567
• remove inline styles
  • [Markdown] [Learn] Remove (most) inline styles #9571
• make note/warning consistently formatted:
  • [Markdown] [Learn] Fix notes that have a misplaced colon #9391
  • [Markdown] [Learn] Convert notes to callouts #9393
  • [Markdown] [Learn] Fix heading-style notes #9394
  • [Markdown] [Learn] Fix remaining Learn area notes #9397
  • [Markdown] [Learn] Fix warnings #9568
• fix broken dl elements
  • [Markdown] [Learn] Fix dl elements #9570
• deal with sup and sub
  • [Markdown] [Learn] More Markdown fixes for Learn area #9594
• fix live samples that use IDs which are not simple derivations of heading text
  • [Markdown] [Learn] Adjust live sample calls to match generated heading ids #9609
• remove random CSS classes
  • [Markdown] [Learn] Clean up classes #9573
• remove unsupported elements
  • [Markdown] [Learn] More Markdown fixes for Learn area #9594
• ensure tables are converted appropriately
  • [Markdown] Prepare Learn docs for Markdowning #9218 (comment)
  • [Markdown] [Learn] Suppress conversion for wide tables #9604
• fix broken <strong><code> markup, and other inline markup issues
  • none found

[wbamberg]

This comment is an analysis of <table> conversion in the Learn area.

There are 290 tables in the Learn docs. h2m can convert just 37 of them.

As usual, there are two questions to answer here:

• are there many currently unconvertible tables we could make convertible, given a bit of work?
• are there some tables that are currently getting converted, that should not be?

Converting more tables

290-37 = 253 tables are unconverted. Of these, 220 are tables of a particular form, like this:

Tables like this are not convertible because they have a header column, and I think this design is an editorial choice we should respect. So there's only at most 33 tables that might be made convertible. I've had a look through these, and I don't think it makes sense to try to make them convertible - they are generally unconvertible because they have cells containing block elements, or header columns, or other good reasons.

Converting fewer tables

The good reason for not converting tables that could be converted is that their GFM representation would be too wide to be readable, per https://developer.mozilla.org/en-US/docs/MDN/Contribute/Markdown_in_MDN#gfm_table_maximum_width.

Of the 37 convertible tables, 16 have a GFM representation wider than 150 characters, so I'll suppress conversion for those tables: #9604.

[wbamberg]

Converted in #9632.