Added type <Unit> to be consistent with the text

In the text it states that "We explicitly specificy its `Unit` return type" but the code example does not explicitly set it
diff --git a/docs/basics.md b/docs/basics.md
index f1f7aa7..29e9ae9 100644
--- a/docs/basics.md
+++ b/docs/basics.md
@@ -125,7 +125,7 @@
 <div class="sample" markdown="1" theme="idea" data-highlight-only>
 
 ```kotlin
-fun main(args: Array<String>) = runBlocking { // start main coroutine
+fun main(args: Array<String>) = runBlocking<Unit> { // start main coroutine
     GlobalScope.launch { // launch new coroutine in background and continue
         delay(1000L)
         println("World!")