Update docs/Configuration.md

Co-authored-by: Bryan Conn <[email protected]>

docs/Configuration.md

@@ -233,7 +233,7 @@ trigger:
     max_random_delay: 0
 ```
 
-For `onstartup`, it has a optional field, _min_size_. It indicates the minimum size the file must have to roll over. A size of zero will cause a roll over no matter what the file size is. The default value is 1, which will prevent rolling over an empty file.
+For `onstartup`, it has an optional field, _min_size_. It indicates the minimum size the file must have to roll over. A size of zero will cause a roll over no matter what the file size is. The default value is 1, which will prevent rolling over an empty file.
 
 i.e.