Fixed a typo in documentation in Database.md

From: `Each file an migrations folder need`
To: `Each file in migrations folder need`

Signed-off-by: Monish <monish.gupta1@gmail.com>

docs/Guides/Database.md

@@ -245,7 +245,7 @@ for Postgres, MySQL, SQL Server and SQLite. For MongoDB migrations, please check
 #### [Postgrator](https://www.npmjs.com/package/postgrator)
 
 Postgrator is Node.js SQL migration tool that uses a directory of SQL scripts to
-alter the database schema. Each file an migrations folder need to follow the
+alter the database schema. Each file in migrations folder need to follow the
 pattern: ` [version].[action].[optional-description].sql`.
 
 **version:** must be an incrementing number (e.g. `001` or a timestamp).