update logging adapter docs (#647)

README.md

@@ -54,6 +54,7 @@ All paths should work with `go get <path>`.
   * [`github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus`⚡](providers/prometheus) - Prometheus client-side and server-side monitoring middleware. Supports exemplars. Moved from deprecated now [`go-grpc-prometheus`](https://github.com/grpc-ecosystem/go-grpc-prometheus).
   * (external) [`go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc`](https://go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc) - official OpenTelemetry interceptors (metric and tracing).
 * Logging with [`github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/logging`](interceptors/logging) - a customizable logging middleware offering extended per request logging. It requires logging adapter, see examples in [`interceptors/logging/examples`](interceptors/logging/examples) for `go-kit`, `log`, `logr`, `logrus`, `slog`, `zap` and `zerolog`.
+  * NOTE: Interceptors with [context](https://pkg.go.dev/context) field injections need to be chained before the adapter function.
 * Tracing:
   * (external) [`go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc`](https://go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc) - official OpenTelemetry interceptors (metric and tracing) as used in [example](examples).
   * (external) [`github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing`](https://pkg.go.dev/github.com/grpc-ecosystem/[email protected]/tracing/opentracing) - deprecated [OpenTracing](http://opentracing.io/) client-side and server-side interceptors if you still need it!