feat: migrate shortcodes to zola components

[kbvernon]

Part 4 of 5 — Zola component migration.

1. #N1 chore: fonts and lockfile
2. #N2 fix: scroll-margin
3. #N3 content: markdown tables
4. #N4 feat: Zola components
5. #N5 refactor: get_taxonomy

Merge in order.

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This is the main upgrade. CI and template syntax have to move together, hence one large PR rather than several small ones.

CI — replaces the pinned 0.22.1 curl install with taiki-e/install-action for just and zola, and calls just build instead of zola build, which builds the tailwind css first.

Templates — templates/shortcodes/ becomes templates/components/. Currently, only includes callout and version components, the latter to standardize version updating. The raw_table and load_table shortcodes are gone because of #N3. The macros.html template is also removed. The guide component is now defined in sidebar.html, the only place it is used, and page.html inlines the TOC markup that macros::toc_items used to render.

CSS — .z-code becomes .giallo, matching the class prefix the newer Zola derives from the highlight theme name.

Content — Had to gsub all the macro calls in markdown content and replace with, e.g., {% <callout type="x"> %}, which I must say, is a much much better syntax. This is the bulk of the diff.

[JosiahParry]

nice callout utility