Docs: update: rename "Debug suspend functions" to "Optimised-out variables"

Author: PetrakovichVictoria

docs/topics/debug-coroutines-with-idea.md

@@ -101,7 +101,7 @@ The tutorial assumes you have prior knowledge of the [coroutines](coroutines-gui
 
 Using IntelliJ IDEA debugger, you can dig deeper into each coroutine to debug your code.
 
-### Debug suspend functions
+### Optimised-out variables
 
 If you use `suspend` functions, in the debugger, you might see the "was optimised out" text next to a variable's name:
 

docs/topics/debug-flow-with-idea.md

@@ -102,7 +102,7 @@ Create a Kotlin [flow](https://kotlinlang.org/api/kotlinx.coroutines/kotlinx-cor
 
     ![Debug the coroutine](flow-debug-2.png)
 
-### Debug suspend functions
+### Optimised-out variables
 
 If you use `suspend` functions, in the debugger, you might see the "was optimised out" text next to a variable's name: