feat: hel: render without execute

package/c/hel/hel--0.1.sql

@@ -0,0 +1,26 @@
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION hel" to load this file. \quit
+
+CREATE SCHEMA hel;
+
+-- Define the parse_text_with_hectic function that uses hectic library
+-- Expected usage:
+--   ```sql
+--    SELECT "hel"."render"(
+--      "declare" := 
+--        jsonb_build_object(
+--          'name', 'test',
+--          'config', jsonb_build_object(
+--            'debug', true,
+--            'limit', 100
+--          )
+--        ),
+--      "template" := $hel$
+--        {{ name }} {{ config.limit }}
+--      $hel$
+--    ); 
+--   ```
+CREATE FUNCTION "hel"."render"("declare" json, "template" text)
+RETURNS text
+AS 'hel', 'render'
+LANGUAGE C STRICT;