docs: add @todo

Author: kenjis

system/Database/Postgre/Connection.php

@@ -65,6 +65,9 @@ public function connect(bool $persistent = false)
         }
 
         // Convert DSN string
+        // @TODO This format is for PDO_PGSQL.
+        //      https://www.php.net/manual/en/ref.pdo-pgsql.connection.php
+        //      Should deprecate?
         if (mb_strpos($this->DSN, 'pgsql:') === 0) {
             $this->convertDSN();
         }

tests/system/Database/ConfigTest.php

@@ -198,6 +198,9 @@ public function testConnectionGroupWithDSNPostgreNative(): void
      */
     public function testConvertDSN(string $input, string $expected): void
     {
+        // @TODO This format is for PDO_PGSQL.
+        //      https://www.php.net/manual/en/ref.pdo-pgsql.connection.php
+        //      Should deprecate?
         $this->dsnGroupPostgreNative['DSN'] = $input;
         $conn                               = Config::connect($this->dsnGroupPostgreNative, false);
         $this->assertInstanceOf(BaseConnection::class, $conn);