[Storybook] Fix docs (and enable TOC on stories) (#2565)

## Summary:

@third [noticed](#2543 (comment)) that our Storybook docs weren't working anymore. This is a regression that happened during the Storybook v9 upgrade. 

This PR fixes autodocs (and enables the TOC feature which is a nice little addition). 


Issue: "none"

## Test plan:

`pnpm install; pnpm start` -> stories have a "Docs" entry again

Author: jeremywiebe

Reviewers: SonicScrewdriver

Required Reviewers:

Approved By: SonicScrewdriver

Checks: ✅ 8 checks were successful

Pull Request URL: #2565

Author: jeremywiebe

.changeset/odd-moose-hope.md

@@ -0,0 +1,2 @@
+---
+---

.storybook/main.ts

@@ -38,8 +38,11 @@ const config: StorybookConfig = {
         // dir.
         "../packages/*/src/**/*@(.stories|.fixturestories).@(ts|tsx)",
     ],
-
-    addons: ["@storybook/addon-links", "@storybook/addon-a11y"],
+    addons: [
+        "@storybook/addon-a11y",
+        "@storybook/addon-docs",
+        "@storybook/addon-links",
+    ],
 
     // NOTE(kevinb): We customize the padding a bit so that so that stories
     // using the on-screen keypad render correctly.  Storybook adds its own

.storybook/preview.tsx

@@ -87,6 +87,9 @@ const preview: Preview = {
                 value,
             })),
         },
+        docs: {
+            toc: true,
+        },
     },
     tags: [
         //👇 Enables auto-generated documentation for all stories

package.json

@@ -32,6 +32,7 @@
         "@rollup/plugin-swc": "^0.4.0",
         "@sheerun/mutationobserver-shim": "^0.3.3",
         "@storybook/addon-a11y": "^9.0.4",
+        "@storybook/addon-docs": "^9.0.5",
         "@storybook/addon-links": "^9.0.4",
         "@storybook/react-vite": "^9.0.4",
         "@swc-node/register": "^1.10.10",