generate rest API with redoc

via custom template

docs/source/reference/rest-api.md

@@ -1,33 +1,14 @@
-<!---
-This doc is part of the API references section of the References documentation.
---->
+---
+page_template: redoc.html
+# see: https://redocly.com/docs/redoc/config/ for options
+redoc_options:
+  hideHostname: true
+  hideLoading: true
+---
 
 (jupyterhub-rest-API)=
 
 # JupyterHub REST API
 
-Below is an interactive view of JupyterHub's OpenAPI specification.
-
-<!-- client-rendered openapi UI copied from FastAPI -->
-
-<link type="text/css" rel="stylesheet" href="https://cdn.jsdelivr.net/npm/swagger-ui-dist@3/swagger-ui.css">
-<script src="https://cdn.jsdelivr.net/npm/swagger-ui-dist@4.1/swagger-ui-bundle.js"></script>
-<!-- `SwaggerUIBundle` is now available on the page -->
-
-<!-- render the ui here -->
-<div id="openapi-ui"></div>
-
-<script>
-const ui = SwaggerUIBundle({
-  url: '../_static/rest-api.yml',
-  dom_id: '#openapi-ui',
-  presets: [
-    SwaggerUIBundle.presets.apis,
-    SwaggerUIBundle.SwaggerUIStandalonePreset
-  ],
-  layout: "BaseLayout",
-  deepLinking: true,
-  showExtensions: true,
-  showCommonExtensions: true,
-});
-</script>
+NOTE: The contents of this markdown file are not used,
+this page is entirely generated from `_templates/redoc.html` and `_static/rest-api.yml`