docs: improvements to API reference intro sections (#9397)

- Improve intro sections of API reference to utilize divided columns
- Improve the content of the intro sections
- Add a new Workflows section to explain the workflows badge and how to use it
- Fixes to headings and add anchor for copying the link to a section
- Fixes responsiveness of intro sections on mobile devices
- Other: fix loading not showing when a sidebar category is opened.

Closes DOCS-932, DOCS-934, DOCS-937

Preview: https://api-reference-v2-git-docs-api-ref-intro-fixes-medusajs.vercel.app/v2/api/store

www/apps/api-reference/app/_mdx/client-libraries.mdx

@@ -1,20 +1,21 @@
+import { H3 } from "docs-ui"
 import Space from "@/components/Space"
 import DownloadFull from "@/components/DownloadFull"
 
-### Just Getting Started?
+<H3 className="!mt-0">Just Getting Started?</H3>
 
-Check out the [quickstart guide](https://docs.medusajs.com/create-medusa-app).
+Check out the [Medusa v2 Documentation](https://docs.medusajs.com/v2).
 
 <Space bottom={8} />
 
 <Note type="soon">
 
-Support for v2 API Routes is coming soon in Medusa JS Client and Medusa React.
+JavaScript client libraries are coming soon for Medusa v2.
 
 </Note>
 
 ### Download Full Reference
 
-Download this reference as an OpenApi YAML file. You can import this file to tools like Postman and start sending requests directly to your Medusa backend.
+Download this reference as an OpenApi YAML file. You can import this file to tools like Postman and start sending requests directly to your Medusa application.
 
 <DownloadFull />