Plugin listings in plugins/index.md and getting-started/whats-new.md
are now generated from .base files that query plugin docs by their tags.
This prevents the tables from going out of sync when plugins are added
or updated. Added new-in-v5 frontmatter property to 8 plugin docs for
the what's-new page filter.
Covers the plugin ecosystem, YAML configuration, Obsidian compatibility,
page type system, layout system, performance, CLI, i18n, new plugins,
and plugin development changes. Also updates home page clone command
for v5 as default branch.