Update sources/platform/actors/running/store.md

Co-authored-by: TheoVasilis <98097738+TheoVasilis@users.noreply.github.com>

Author: mhamas

sources/platform/actors/running/store.md

@@ -138,7 +138,7 @@ On the top of that, you can see how much you have been charged for a specific ru
 
 ![Run cost shown on the overview of all runs](./images/store/pay_per_result_run_list.png)
 
-If you wish to see how much you have been charged for a particular actor, you will find this information
+If you wish to see how much you have been charged for a particular Actor, you will find this information
 on the bottom of the [Usage tab](https://console.apify.com/billing).
 
 ![Actor pay-per-result cost](./images/store/pay_per_result_actor_items.png)