Add Replay to Web BE SDK Docs

[jas-kas]

As we mention on Session Replay Set Up docs:

This includes static websites, single-page-aplications and also server-side-rendered, that includes frameworks such as: Django, Spring, ASP.NET, Laravel, Express and Rails. If you don't use npm or yarn, you can use our Loader script tag on your main HTML template.

Replay does support web BE depending on your app. However, we don't mention it on those dedicated web BE SDK docs.

This ticket is to add a callout to Replay in Web BE SDK docs.

Ryan's suggestion: If we do docs callouts from backend web frameworks, we should also update/create a page with more loader-specific examples.

[getsantry]

Routing to @getsentry/product-owners-replays for triage ⏲️

[mydea]

So we'll add this for django first, as a separate section in the sidebar at the very bottom, with a single item. This will show the snippet to add the loader and link out to browser JS docs for more info/config about replay.

[jas-kas]

@mydea is there someone on the docs/sdk team you could pass this off too? thank you