Nicer docusaurus openapi docs (#722)

- uses this plugin (https://github.com/cloud-annotations/docusaurus-openapi) to make a nice static site docusaurus based api section of docs site.
- adds some nicer postman code snippets etc too as part of api docs.
- makes api docs more "self hosted" as opposed to the dynamic swagger url approach.

docs/docusaurus.config.js

@@ -32,12 +32,15 @@ const config = {
 
   presets: [
     [
-      "classic",
+      "docusaurus-preset-openapi",
       /** @type {import('@docusaurus/preset-classic').Options} */
       ({
         docs: {
           sidebarPath: require.resolve("./sidebars.js"),
         },
+        api: {
+          path: "docs/api/openapi.json",
+        },
         blog: false,
         theme: {
           customCss: require.resolve("./src/css/custom.css"),
@@ -62,11 +65,7 @@ const config = {
             position: "left",
             label: "Docs",
           },
-          {
-            href: "https://editor.swagger.io/?url=https://raw.githubusercontent.com/LAION-AI/Open-Assistant/main/docs/docs/api/openapi.json",
-            label: "API",
-            position: "left",
-          },
+          { to: "/api", label: "API", position: "left" },
           {
             href: "https://github.com/LAION-AI/Open-Assistant",
             label: "GitHub",