Add sample for converting coroutine to RxJava 2 Completable

src/main/kotlin/interop/completable/CompletableInterop.kt

@@ -1,2 +1,17 @@
 package interop.completable
 
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.rx2.rxCompletable
+import kotlin.coroutines.CoroutineContext
+
+class CompletableInterop(
+    override val coroutineContext: CoroutineContext = Dispatchers.Default
+): CoroutineScope {
+    fun doWork() = CoroutineScope(coroutineContext).rxCompletable {
+        delay(1000)
+        println("Hello from the coroutine!")
+    }
+}
+

src/main/kotlin/interop/completable/TestCompletableInterop.kt

@@ -0,0 +1,9 @@
+package interop.completable
+
+fun main() {
+    println("Creating an instance of CompletableInterop")
+    val completableInterop = CompletableInterop()
+    completableInterop.doWork().subscribe()
+
+    Thread.sleep(2000) // Sleep the main thread to await the completion of the background thread
+}