Fix typo in docs

Author: cschleiden

docs/commands.md

@@ -17,7 +17,7 @@ This will cause the command to **not** produce another event when the workflow y
 
 ## States & Transitions
 
-Commands are a simpel state machine and their states and transitions are the following:
+Commands are a simple state machine and their states and transitions are the following:
 
 ![](./commands.drawio.png)
 
@@ -26,4 +26,4 @@ Commands are a simpel state machine and their states and transitions are the fol
   - ScheduleTimer
 
 - No all commands are committable, the ones which aren't are:
-  - Sideeffect
+  - Sideeffect