Add initial package.json for docs with build script (#2221)

docs/package.json

@@ -0,0 +1,8 @@
+{
+  "private": true,
+  "name": "docs",
+  "version": "1.0.0",
+  "scripts": {
+    "build": "mkdir -p dist && echo '' > dist/index.html"
+  }
+}

pnpm-workspace.yaml

@@ -1,4 +1,5 @@
 packages:
   - core
   - preview
+  - docs
   - 'shared/*'