Use correct wording in shared-mutable-state-and-concurrency.md (#2734)

Using Dispatchers.Default we can make the coroutines run *parallelly*.

Co-authored-by: Vsevolod Tolstopyatov <[email protected]>
Co-authored-by: dkhalanskyjb <[email protected]>

Author: 3 people

docs/topics/shared-mutable-state-and-concurrency.md

@@ -2,8 +2,8 @@
 
 [//]: # (title: Shared mutable state and concurrency)
 
-Coroutines can be executed concurrently using a multi-threaded dispatcher like the [Dispatchers.Default]. It presents
-all the usual concurrency problems. The main problem being synchronization of access to **shared mutable state**. 
+Coroutines can be executed parallelly using a multi-threaded dispatcher like the [Dispatchers.Default]. It presents
+all the usual parallelism problems. The main problem being synchronization of access to **shared mutable state**. 
 Some solutions to this problem in the land of coroutines are similar to the solutions in the multi-threaded world, 
 but others are unique.
 
@@ -510,4 +510,4 @@ have to switch to a different context at all.
 [actor]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.channels/actor.html
 [produce]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.channels/produce.html
 
-<!--- END -->
+<!--- END -->