Enable remark-gfm for MDX table rendering in Storybook

Tables in .mdx attribute reference docs were not rendering because
Storybook's MDX v2 parser doesn't support GFM tables by default.
Adds remark-gfm plugin and configures addon-docs separately from
addon-essentials so the plugin options are respected.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: b3008

.storybook/main.ts

@@ -1,8 +1,27 @@
 import type { StorybookConfig } from "@storybook/web-components-vite";
+import remarkGfm from "remark-gfm";
 
 const config: StorybookConfig = {
   stories: ["../src/**/*.mdx", "../src/**/*.stories.@(js|jsx|mjs|ts|tsx)"],
-  addons: ["@storybook/addon-links", "@storybook/addon-essentials"],
+  addons: [
+    "@storybook/addon-links",
+    {
+      name: "@storybook/addon-essentials",
+      options: {
+        docs: false,
+      },
+    },
+    {
+      name: "@storybook/addon-docs",
+      options: {
+        mdxPluginOptions: {
+          mdxCompileOptions: {
+            remarkPlugins: [remarkGfm],
+          },
+        },
+      },
+    },
+  ],
   framework: {
     name: "@storybook/web-components-vite",
     options: {},