docs: add Node.js requirement, footnotes, and Obsidian plugin support table

- Add Node.js 22 prerequisite callout to installation guide
- Document footnote support via GFM plugin
- Add Obsidian community plugin support table (Dataview, Excalidraw, Leaflet)

docs/features/Obsidian compatibility.md

@@ -194,6 +194,29 @@ Video files can be embedded using standard image syntax:
 
 By default, Obsidian does not render its Markdown syntax inside HTML blocks. Quartz extends this with the `enableInHtmlEmbed` option, which parses wikilinks, highlights, and tags inside raw HTML nodes.
 
+### Footnotes
+
+Footnotes using the `[^1]` syntax are fully supported through the [[GitHubFlavoredMarkdown]] plugin:
+
+```markdown
+Here is a sentence with a footnote.[^1]
+
+[^1]: This is the footnote content.
+```
+
+## Obsidian Community Plugin Support
+
+Quartz focuses on supporting Obsidian's core features. Functionality from Obsidian community plugins is handled by Quartz community plugins:
+
+| Obsidian Plugin | Quartz Support |
+| --------------- | -------------- |
+| Dataview | Supported via [Quartz Syncer](https://community.obsidian.md/plugins/quartz-syncer) — exports Dataview queries as static content during sync |
+| Excalidraw | Planned as a future community plugin |
+| Leaflet Maps | Supported via the `obsidian-plugin-leaflet` community plugin |
+
+> [!tip]
+> As a general rule: Obsidian core features are supported by Quartz directly, while Obsidian community plugin features are supported by corresponding Quartz community plugins.
+
 ## Configuration
 
 This functionality is provided by the [[ObsidianFlavoredMarkdown]], [[Frontmatter]] and [[CrawlLinks]] plugins. See the plugin pages for customization options.