docs: add package introductions and the @robonen/crdt guide

An intro.vue landing for all 12 packages, plus a multi-section crdt guide (Concepts, Primitives, Replication & Sync, and an interactive convergence Playground).

configs/tsdown/docs/intro.vue

@@ -0,0 +1,121 @@
+<script setup lang="ts">
+const usageExample = `import { defineConfig } from 'tsdown';
+import { sharedConfig } from '@robonen/tsdown';
+
+export default defineConfig({
+  ...sharedConfig,
+  tsconfig: './tsconfig.src.json',
+  entry: ['src/index.ts'],
+});`;
+
+const overrideExample = `import { defineConfig } from 'tsdown';
+import { sharedConfig } from '@robonen/tsdown';
+import Vue from 'unplugin-vue/rolldown';
+
+export default defineConfig({
+  ...sharedConfig,
+  entry: ['src/index.ts', 'src/*/index.ts'],
+  plugins: [Vue({ isProduction: true })],
+  // layer on top of the shared defaults
+  dts: { vue: true },
+});`;
+</script>
+
+<template>
+  <div class="docs-section">
+    <div class="prose-docs">
+      <h1>@robonen/tsdown</h1>
+      <p class="text-lg text-(--fg-muted)">
+        Shared tsdown build configuration for every <code>@robonen</code>
+        package — one source of truth for output formats, declarations, and
+        bundle hygiene.
+      </p>
+    </div>
+
+    <div class="prose-docs">
+      <p>
+        Every library in this monorepo ships dual ESM/CJS builds with type
+        declarations, a clean <code>dist</code>, and a consistent license
+        banner. Re-declaring that in each package's
+        <code>tsdown.config.ts</code> is repetitive and drifts over time.
+        <code>@robonen/tsdown</code> exports a single
+        <code>sharedConfig</code> object you spread into
+        <code>defineConfig</code>, then add only what is package-specific —
+        usually just <code>entry</code> and <code>tsconfig</code>.
+      </p>
+    </div>
+
+    <div class="grid grid-cols-1 sm:grid-cols-2 gap-4">
+      <div class="rounded-lg border border-(--border) bg-(--bg-subtle) p-5">
+        <h3 class="font-medium text-(--fg) mb-1.5">Dual ESM + CJS</h3>
+        <p class="text-sm text-(--fg-muted) m-0">
+          Emits both <code>esm</code> and <code>cjs</code> formats so packages
+          work in modern bundlers and legacy <code>require</code> setups alike.
+        </p>
+      </div>
+      <div class="rounded-lg border border-(--border) bg-(--bg-subtle) p-5">
+        <h3 class="font-medium text-(--fg) mb-1.5">Types included</h3>
+        <p class="text-sm text-(--fg-muted) m-0">
+          <code>dts: true</code> generates <code>.d.ts</code> declarations on
+          every build — no separate type pipeline to maintain.
+        </p>
+      </div>
+      <div class="rounded-lg border border-(--border) bg-(--bg-subtle) p-5">
+        <h3 class="font-medium text-(--fg) mb-1.5">Clean, stable output</h3>
+        <p class="text-sm text-(--fg-muted) m-0">
+          <code>clean: true</code> wipes <code>dist</code> first and
+          <code>hash: false</code> keeps file names deterministic for
+          predictable publishing.
+        </p>
+      </div>
+      <div class="rounded-lg border border-(--border) bg-(--bg-subtle) p-5">
+        <h3 class="font-medium text-(--fg) mb-1.5">Spread &amp; override</h3>
+        <p class="text-sm text-(--fg-muted) m-0">
+          It is a plain object typed as <code>InlineConfig</code> — spread it,
+          override any field, and let editor autocomplete guide you.
+        </p>
+      </div>
+    </div>
+
+    <div class="prose-docs">
+      <h2>Install</h2>
+      <p>
+        Add the config package and <code>tsdown</code> itself as dev
+        dependencies:
+      </p>
+    </div>
+    <DocsCode :code="`pnpm add -D @robonen/tsdown tsdown`" lang="bash" />
+
+    <div class="prose-docs">
+      <h2>Usage</h2>
+      <p>
+        Create <code>tsdown.config.ts</code> in your package, spread
+        <code>sharedConfig</code>, and supply your entry points:
+      </p>
+    </div>
+    <DocsCode :code="usageExample" lang="ts" />
+
+    <div class="prose-docs">
+      <p>
+        Because <code>sharedConfig</code> is a normal object, you can override
+        or extend any field after spreading — add plugins, extra entries, or
+        tweak the declaration options:
+      </p>
+    </div>
+    <DocsCode :code="overrideExample" lang="ts" />
+
+    <div class="rounded-lg border border-(--border) bg-(--bg-elevated) p-5">
+      <h3 class="font-medium text-(--fg) mb-2">Where to next</h3>
+      <ul class="text-sm text-(--fg-muted) space-y-1.5 list-disc pl-5 m-0">
+        <li>
+          <NuxtLink to="/tsdown/overview" class="text-(--accent-text) hover:underline">sharedConfig</NuxtLink>
+          — the full list of defaults and their exact values.
+        </li>
+        <li>
+          Read the guide sections below for the conventions baked into the
+          shared build and tips for package-specific overrides.
+        </li>
+      </ul>
+    </div>
+  </div>
+</template>