libgis: add doxygen note about general/g.parser/standard_option.c

         (merge https://trac.osgeo.org/grass/changeset/61789 & https://trac.osgeo.org/grass/changeset/61821 from trunk)


git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@61822 15284696-431f-4ddb-bdfa-cd5b030d7da7

include/gis.h

@@ -191,9 +191,12 @@ static const char *GRASS_copyright __attribute__ ((unused))
   that the map is not supposed to exist and that module will create one.
 
   Used by the G_parser() system.
-*/
 
-/**/ typedef enum
+  IMPORTANT NOTE: when adding new item to STD_OPT you should also
+  update STD_OPT_STRINGS array in general/g.parser/standard_option.c.
+
+*/
+typedef enum
 {
     G_OPT_UNDEFINED,
     G_OPT_DB_SQL,		/*!< SQL statements */