Upgrade unified deps and improve unified plugins types (#1200)

* Upgrade @astrojs/markdown-support deps and update types

* Add changeset

* Update changeset

* Switch astro-markdown-plugins example to use rehype-autolink-headings

Usage of remark-autolink-headings is discouraged in favor of the rehype counterpart: https://github.com/remarkjs/remark-autolink-headings\#remark-autolink-headings

* Add stricter types for unified plugins

This includes a few suggestions from a code review:
- use vfile.toString instead of vfile.value.toString
- refactor plugins to follow unified best practices instead of returning functions that return a plugin
- use any instead of any[] for plugin options types

* Narrow down types to more specific hast or mdast typings

1 files changed, 1 insertions, 1 deletions

diff --git a/packages/markdown-support/src/load-plugins.ts b/packages/markdown-support/src/load-plugins.ts
index df19a082e..5b24f14f6 100644
--- a/packages/markdown-support/src/load-plugins.ts
+++ b/packages/markdown-support/src/load-plugins.ts
@@ -9,7 +9,7 @@ async function importPlugin(p: string | UnifiedPluginImport): UnifiedPluginImpor
   return await p;
 }
 
-export function loadPlugins(items: Plugin[]): Promise<[unified.Plugin] | [unified.Plugin, unified.Settings]>[] {
+export function loadPlugins(items: Plugin[]): Promise<[unified.Plugin] | [unified.Plugin, any]>[] {
   return items.map((p) => {
     return new Promise((resolve, reject) => {
       if (Array.isArray(p)) {