Add water name layer

layers/water_name/merge_lakelines.sql

@@ -0,0 +1,9 @@
+CREATE TABLE IF NOT EXISTS osm_water_lakeline AS (
+	SELECT wp.osm_id,
+		ll.wkb_geometry AS geometry,
+		name, name_en
+    FROM osm_water_polygon AS wp
+    INNER JOIN lake_centerline ll ON wp.osm_id = ll.osm_id
+);
+
+CREATE INDEX IF NOT EXISTS osm_water_lakeline_geometry_idx ON osm_water_lakeline USING gist(geometry);