api2/types: add type_text to DATASTORE_MAP_FORMAT

This way we get a better rendering in the api-viewer.
before:
 [<string>, ... ]

after:
 [(<source>=)?<target>, ... ]

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/api2/types/mod.rs

@@ -365,6 +365,7 @@ pub const DATASTORE_MAP_SCHEMA: Schema = StringSchema::new("Datastore mapping.")
     .format(&DATASTORE_MAP_FORMAT)
     .min_length(3)
     .max_length(65)
+    .type_text("(<source>=)?<target>")
     .schema();
 
 pub const DATASTORE_MAP_ARRAY_SCHEMA: Schema = ArraySchema::new(