fix: missing doc update (#51)

Signed-off-by: Anthony TREUILLIER <anthony.treuillier.ext@orange.com>

Author: antrema

docs/guides/zones.md

@@ -9,6 +9,7 @@ The specification of the `Zone` contains the following fields:
 | kind | string | Y | Kind of the zone, one of "Native", "Master", "Slave", "Producer", "Consumer" |
 | nameservers | []string | Y | List of the nameservers of the zone |
 | catalog | string | N | The catalog this zone is a member of |
+| soa_edit_api | string | N | The SOA-EDIT-API metadata item, one of "DEFAULT", "INCREASE", "EPOCH", defaults to "DEFAULT" |
 
 ## Example
 
@@ -23,4 +24,5 @@ spec:
     - ns2.helloworld.com
   kind: Master
   catalog: catalog.helloworld
+  soa_edit_api: EPOCH
 ```