Update README.md

Author: damalis

README.md

@@ -159,7 +159,7 @@ Edit the `.env` file to change values of
  </tr>
  <tr>
  <td><code>DATABASE_CONT_NAME</code></td>
- <td colspan="2"><code>mariadb</code>, <code>mysql</code> or <code>custom name</code></td>
+ <td colspan="2"><code>mariadb</code>, <code>mysql</code> or <code><a href="https://docs.docker.com/reference/compose-file/services/#container_name" rel="nofollow" alt="custom name">custom name</a></code></td>
  </tr>
  <tr>
  <td rowspan="2"><code>DATABASE_PACKAGE_MANAGER</code></td>