specify config nesting

The term "under" is overloaded. Sometimes it means "nested within", and sometimes it means "as the next section after this one".

This small change reduces ambiguity.

Author: alexfornuto

step-ca/basic-certificate-authority-operations.mdx

@@ -193,7 +193,7 @@ $ step ca certificate localhost localhost.crt localhost.key --not-after=5m
 $ step ca certificate localhost localhost.crt localhost.key --not-before=5m --not-after=240h
 ```
 
-Note that default maximum certificate duration is 24 hours. To adjust the global default, minimum, and maximum certificate durations for your CA, add a `claims` section to the `$(step path)/config/ca.json` configuration file, under `"authority"`, with the following keys:
+Note that default maximum certificate duration is 24 hours. To adjust the global default, minimum, and maximum certificate durations for your CA, add a `claims` section to the `$(step path)/config/ca.json` configuration file, nested under `"authority"`, with the following keys:
 
 ```json
 "claims": {