Update example to use npm package for postgres (#1379)

examples/scripts/postgres.ts

@@ -3,30 +3,29 @@
  * @difficulty intermediate
  * @tags cli, deploy
  * @run --allow-net --allow-env <url>
- * @resource {https://deno-postgres.com/} Deno Postgres docs
- * @resource {https://deno.land/x/postgres} Deno Postgres on deno.land/x
  * @group Databases
  *
- * Using the Deno Postgres client, you can connect to a Postgres database
+ * Using the npm Postgres client, you can connect to a Postgres database
  * running anywhere.
  */
 
-// Import the Client constructor from deno.land/x
-import { Client } from "https://deno.land/x/postgres@v0.17.0/mod.ts";
+// Import the Postgres package from
+import postgres from "npm:postgres";
 
 // Initialize the client with connection information for your database, and
 // create a connection.
-const client = new Client({
+const sql = postgres({
   user: "user",
   database: "test",
   hostname: "localhost",
   port: 5432,
 });
-await client.connect();
 
 // Execute a SQL query
-const result = await client.queryArray("SELECT ID, NAME FROM PEOPLE");
-console.log(result.rows); // [[1, 'Carlos'], [2, 'John'], ...]
+const result = await sql`
+  SELECT ID, NAME FROM PEOPLE
+`;
+console.log(result);
 
 // Close the connection to the database
-await client.end();
+await sql.end();