feat: showcase

[OzakIOne]

Pre-flight checklist

• I have read the Contributing Guidelines on pull requests.
• If this is a code change: I have written unit tests and/or added dogfooding pages to fully verify the new behavior.
• If this is a new API or substantial change: the PR has an accompanying issue (closes #0000) and the maintainers have approved on my working plan.

Motivation

• a page per site
  • a site = 1 yaml or markdown file in a folder for images
    • add support for linking local images
• file tags.yaml
• custom attributes in yaml / frontmatter
• good plugin code / file structure (take example on docs/blog)
• pluginId ?
• merge https://github.com/facebook/docusaurus/tree/ozaki/showcaseSites

Test Plan

• add tests
  • add more test and cover more cases

Test links

Deploy preview & tests

showcaseAll

Related issues/PRs

#6882

[netlify]

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[github-actions]

⚡️ Lighthouse report for the deploy preview of this PR

URL	Performance	Accessibility	Best Practices	SEO	PWA	Report
/	🟠 64	🟢 98	🟢 96	🟢 100	🟠 88	Report
/docs/installation	🟠 60	🟢 96	🟢 100	🟢 100	🟠 88	Report
/docs/category/getting-started	🟠 76	🟢 100	🟢 100	🟢 90	🟠 88	Report
/blog	🟠 67	🟢 100	🟢 100	🟢 90	🟠 88	Report
/blog/preparing-your-site-for-docusaurus-v3	🟠 63	🟢 96	🟢 100	🟢 100	🟠 88	Report
/blog/tags/release	🟠 67	🟢 100	🟢 100	🟠 80	🟠 88	Report
/blog/tags	🟠 77	🟢 100	🟢 100	🟢 90	🟠 88	Report

[github-actions]

Size Change: +3.32 kB (0%)

Total Size: 1.59 MB

Filename	Size	Change
website/.docusaurus/docusaurus.config.mjs	26.8 kB	+95 B (0%)
website/.docusaurus/registry.js	248 kB	+771 B (0%)
website/.docusaurus/routes.js	156 kB	+107 B (0%)
website/.docusaurus/routesChunkNames.json	109 kB	+134 B (0%)
website/.docusaurus/site-metadata.json	2.33 kB	+154 B (+7%)	🔍
website/build/assets/css/styles.********.css	114 kB	+1.36 kB (+1%)
website/build/assets/js/main.********.js	808 kB	+704 B (0%)

ℹ️ View Unchanged

Filename	Size	Change
website/.docusaurus/codeTranslations.json	2 B	0 B
website/.docusaurus/globalData.json	91.2 kB	0 B
website/.docusaurus/i18n.json	930 B	0 B
website/build/index.html	38 kB	+1 B (0%)

_{compressed-size-action}

[OzakIOne]

Been trying to process markdown showcase page however I don't understand the logic looking at plugin page,
loadContent returns

return {
	type: 'mdx',
	permalink,
	source: aliasedSourcePath,
	title: frontMatter.title ?? contentTitle,
	description: frontMatter.description ?? excerpt,
	frontMatter,
	unlisted,
};

and contentLoaded does this :

      await Promise.all(
        content.map(async (metadata) => {
          const {permalink, source} = metadata;
          const routeMetadata = createPageRouteMetadata(metadata);
          if (metadata.type === 'mdx') {
            await createData( // ozaki: why dont we store this value in a const and then pass it to addRoute modules.content ?
              // Note that this created data path must be in sync with
              // metadataPath provided to mdx-loader.
              `${docuHash(metadata.source)}.json`,
              JSON.stringify(metadata, null, 2),
            );
            addRoute({
              path: permalink,
              component: options.mdxPageComponent, // ozaki: how does the content is rendered in the component ? 
              exact: true,
              metadata: routeMetadata,
              modules: {
                content: source, // ozaki: how does the content is a aliasedPath ?
              },
            });
          } else {
		// process things that are not mdx
          }
        }),
      );
      ```

[OzakIOne]

Trying to implement image insertion, let's say we have this file structure :

website/
	src/
		showcase/
			site/
				site.yml
				preview.jpg

I wonder how to resolve the image path when rendering to the component, I've made it work with the assets folder but I think its better to let preview images aside .yml files