add etldoc to layer_poi

layers/poi/layer.sql

@@ -1,3 +1,7 @@
+
+-- etldoc: layer_poi[shape=record fillcolor=lightpink, style="rounded,filled",  
+-- etldoc:     label="layer_poi | <z14_> z14_" ] ;
+
 CREATE OR REPLACE FUNCTION layer_poi(bbox geometry, zoom_level integer, pixel_width numeric)
 RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, class text, subclass text, "rank" int) AS $$
     SELECT osm_id, geometry, name, NULLIF(name_en, ''), poi_class(subclass) AS class, subclass,
@@ -5,6 +9,7 @@ RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, class t
             PARTITION BY LabelGrid(geometry, 100 * pixel_width)
             ORDER BY poi_class_rank(poi_class(subclass)) ASC, length(name) DESC
         )::int AS "rank"
+    -- etldoc: osm_poi_point ->  layer_poi:z14_        
     FROM osm_poi_point
     WHERE geometry && bbox
       AND zoom_level >= 14

layers/poi/mapping.yaml

@@ -1,4 +1,5 @@
 tables:
+  # etldoc: imposm3 -> osm_poi_point
   poi_point:
     type: point
     fields: