horsegen: generate koka id lists as public

horsegen/uma.kk.template

@@ -14,7 +14,7 @@ extern create-id-table(): vector<int>
   c inline "int32_t arr[] = { {{- range $uma := $.Umas }}{{ $uma.ID }},{{ end -}} };\nkk_vector_from_cint32array(arr, (kk_ssize_t){{ $.UmaCount }}, kk_context())"
   js inline "[{{ range $uma := $.Umas }}{{ $uma.ID }},{{ end }}]"
 // Vector of all Uma IDs in order for easy iterating.
-val vall = once(create-id-table)
+pub val all = once(create-id-table)
 
 // Get the name for an Uma.
 // The name includes the costume variant, e.g. `[Special Dreamer] Special Week`.