small refactorings and cleanups, improved bun/node adapter, updated docs

docs/integration/node.mdx

@@ -0,0 +1,37 @@
+---
+title: 'Node'
+description: 'Run bknd inside Node'
+---
+import InstallBknd from '/snippets/install-bknd.mdx';
+
+## Installation
+Install bknd as a dependency:
+<InstallBknd />
+
+## Serve the API & static files
+The `serve` function of the Node adapter makes sure to also serve the static files required for
+the admin panel.
+
+``` tsx
+// index.js
+import { serve } from "bknd/adapter/node";
+
+// if the configuration is omitted, it uses an in-memory database
+/** @type {import("bknd/adapter/node").NodeAdapterOptions} */
+const config = {
+   connection: {
+      type: "libsql",
+      config: {
+         url: ":memory:"
+      }
+   }
+};
+
+serve(config);
+```
+For more information about the connection object, refer to the [Setup](/setup) guide.
+
+Run the application using node by executing:
+```bash
+node index.js
+```