minimal jquery-ui support (#1178)

* minimal jquery-ui support

* index: true; more docs

Author: mbostock

docs/lib/jquery-ui.md

@@ -0,0 +1,45 @@
+---
+index: true
+---
+
+# jQuery UI
+
+[jQuery UI](https://jqueryui.com/) is a set of user interface interactions, effects, widgets, and themes built on top of the jQuery JavaScript Library.
+
+<link rel="stylesheet" href="npm:jquery-ui/dist/themes/base/jquery-ui.css">
+
+```html run=false
+<link rel="stylesheet" href="npm:jquery-ui/dist/themes/base/jquery-ui.css">
+```
+
+```js echo
+import $ from "npm:jquery";
+self.jQuery = $;
+await import("npm:jquery-ui");
+```
+
+Price range: ${value.join("–")}
+
+```md run=false
+Price range: ${value.join("–")}
+```
+
+<div style="max-width: 320px;" id="slider"></div>
+
+```html run=false
+<div style="max-width: 320px;" id="slider"></div>
+```
+
+```js echo
+const value = Generators.observe((notify) => {
+  const slider = $("#slider");
+  slider.slider({
+    range: true,
+    min: 0,
+    max: 500,
+    values: [5, 300],
+    slide: (event, ui) => notify(ui.values)
+  });
+  notify(slider.slider("values"));
+});
+```

src/npm.ts

@@ -252,6 +252,8 @@ export async function resolveNpmImport(root: string, specifier: string): Promise
       ? "dist/mermaid.esm.min.mjs/+esm"
       : name === "echarts"
       ? "dist/echarts.esm.min.js/+esm"
+      : name === "jquery-ui"
+      ? "dist/jquery-ui.js/+esm"
       : name === "deck.gl"
       ? "dist.min.js/+esm"
       : "+esm"