doc: context utility documentation

Author: RawanMostafa08

docs/internals/utils/context.md

@@ -0,0 +1,34 @@
+# Context Utility
+ 
+## Introduction
+Context Utility provides functions to deal with context creation, callbacks.
+
+## Structure
+
+```go
+	// DefaultTerminateSignals default signals to handle if no signals are provided
+	DefaultTerminateSignals = []os.Signal{
+		syscall.SIGTERM, syscall.SIGHUP, syscall.SIGINT,
+		syscall.SIGQUIT,
+	}
+```
+
+```go
+// WithSignal return a context that is canceled if any of the specified signals was received
+// if no signals are passed, default to DefaultTerminateSignals
+func WithSignal(ctx context.Context, sig ...os.Signal) (context.Context, context.CancelFunc)
+
+
+// OnDone registers a callback on a context when it's done
+// The ctx.Err() is passed as is to the callback function
+func OnDone(ctx context.Context, cb func(error)) 
+```
+
+## Usage
+
+```go
+	ctx, _ := utils.WithSignal(context.Background())
+	utils.OnDone(ctx, func(_ error) {
+		log.Info().Msg("shutting down")
+	})
+```