gin-gonic/examples ? reverse-engineered prompt

Build me a Go repository of ready to run Gin examples and tutorials, like a small collection of sample apps that show how to use Gin in common real world situations.

I want each example to be simple to run on its own and easy to understand, covering things like basic routing, grouping routes, templates, forms and file uploads, cookies, CORS, graceful shutdown, reverse and forward proxies, websocket and server sent events, HTTP2, gRPC, auto TLS, OIDC, OpenTelemetry, rate limiting, validation, and a few realtime chat style demos.

Please keep the code clean and beginner friendly, with a README that explains what each example does and how to run it. If there are any setup details that depend on current Gin or Go docs, look those up online if you need to. Also make sure the repo is organized so each example can be run independently without much extra work.